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THE

RAY SOCIETY.

INSTITUTED MDCCCXLIV.

This volume is issued to the Subscribers to the Ray Society /or

the Year 1880.

LONDON

MDCCCLXXXI.

MONOGRAPH

OF THE

BEITISH APHIDES.

VOL. III.

BY

GEORGE BOWDLER BUCKTON,

FELLOW OF THE KOYAL, LINNEAN, AND CHEMICAL SOCIETIES OF LONDON]

COBRESPONDINQ MEMBER OF THE ACADEMY OF

NATURAL SCIENCES, PHILADELPHIA.

" Servare modum, finemque tenere, naturam scqui.'' — Lucan.

" To keep a mean, to hold the end,
A.ud Nature's conduct to attend."

Quoted by Montaigne.

LONDON:
PRINTED FOR THE RAY SOCIETY.

MDCCCLXXXI.

i R ? r

.^i^V^^'^'^^'H?^

1 V

PBINTED BY 0. E. ADLAKD, BARTHOLOMEW CLOSE.

■2.

PEEFACE

The illustrations of this and former volumes require
a few words of comment. There are high authorities
who may demur to the departure I have made from
precedent as to the posing of my figures. It has been
said that many fine plates of animals and plants have
been rendered useless to science by the artistic render-
ing of a graceful attitude or an elegant curve — that
the figure for science, again, should be representative
or, to a certain extent, abstract. Biological illustra-
tions certainly are not meant to please the eye alone.
Yet no gain can be had by mere naked unclothed facts
in drawing, and if all art is to be eliminated from
science many will turn with disgust from that which
by a better treatment would please. The natural pose
of a bird or reptile can always be connected by an
efficient artist with such scientific details as are capable
of being rendered in the external form. Where the
camera is employed this posing is inseparable from the
representation of living insects ; and after all, notwith-
standing that the views are necessarily perspective,
measurements may be made from them as reliably as
from ordinary eye drawings.

ii PREFACE,

It remains for me cordially to tliank mimerous
friends for liberally helping me witli specimens for
description. Where I have omitted to do this in the
text, I wish here to express my obligations to them.

Weycombe, Haslemere ;

December, 1880

BEITISH APHIDES.

INTRODUCTION.

It is a necessary condition of all Monographs that
they should be classificatory. This department of
biological science is a connecting link between the
work of the anatomist and the theorist, for the labours
of both would be wholly nugatory if identification of
organisms and their relations to each other were
ignored. The systematist is therefore an important
contributor to the advance of all science.

The construction of a true natural classification
requires mental attainments of a high order, and
involves an acquaintance with extensive groups of
living forms. Thus, comparatively few have possessed
the requisite powers of comparison, aptitude to see
correct lines of afiinity, and acuteness to eliminate
characters which, perhaps, showy and obvious in them-
selves, are nevertheless of minor importance. Thus,
the conception of a race, a tribe, or genus, must partake
more or less of an abstract thought, and no two minds,
perhaps, will think alike in all particulars.

In more than one instance I have in this Monograph
been induced, somewhat against my wish, to propose
a new genus upon the evidence of a single species.
Mr. Bentham has warned us of the suspicion which
naturally attaches to such a procedure. Still, if we
concede that nature is not bound by our conceptions of
typical forms, they may be permitted for systematic

2 BEITISH APHIDES.

purposes ; otlierwise to our minds order would revert
to chaos.

Much has yet to be done in comparing and collect-
ting Aphides from other countries, so that there is a
probability that species will yet be discovered to enrich
genera, as yet but poorly represented. The science of
embryology is daily contributing to a sound phylogeny,
which really lies at the root of all natural systems.

The Aphididee seem to extend over all the regions
of the Northern Hemisphere, extending from the
extreme west of Asia, throughout Europe, and across
the entire continent of North America. Species have
been taken, but not as yet identified, on the slopes of
the Himalaya, and probably it only wants attention to
show that they obtain also in the temperate regions
of Africa.

The great problem of the day, and likely to be for
many years hence, is the possible development of higher
out of lower forms. Kant says " Geologists are archaeo-
logists of nature, and the sole irrefragable and direct
evidence of the method by which living things have
been what they are is to be sought amongst fossil
remains."

The great difiiculty that the Entomologist feels in an
appeal to the rocks for evidence, is the comparative
scantiness of specimens hitherto brought to observa-
tion, and the bare indications yielded as to the sequence
of insect orders in the world's history. The fragility
of the bodies of many insects is doubtless one cause of
this imperfection of the record; but, as the ancient
Devonian beds give unmistakable indications of their
occurrence, this branch of the animal kingdom must
have come into existence at a very early stage of time.

The rise of insect life on our globe has been well
treated by several competent writers. The attempt
to introduce so large a subject into this Monograph
would be quite out of place, but briefly it may be
noted that an examination of the most ancient fossils
yet discovered, shows that insects, even at the above

INTRODUCTION. 3

early date, were liighly specialised. The elaborate
veining of the wing of Xenonenra antiqiwrum, which
apparently points to a family combining characters of
a chirping cricket (Orthoptera) and a water-fly (Ephe-
mera)^ leads to the probability that far more simple
forms preceded such, about which there is now no
record.

As might have been expected, the Coleoptera are
the most fully represented in a fossil state ; their dense
elytra and their hard exteriors are less open to disin-
tegration than the softer bodies of the Hemiptera and
Lepidoptera. The Hemiptera would appear to be not
much less ancient than the Orthoptera, for they have
been found in the Carboniferous beds of Great Britain
and America. Singular unions of type again show
themselves in certain examples from the Permian
strata ; such having in their mouth parts, compounded
characters of the mandible and haustellum. Both the
Orthopterous and Hemipterous orders are represented
in the genus Eugeria.

Most of the strata in an ascending series from the
Devonian, show more or less an abundance of insect
remains, but perhaps the Liassic and Oolitic forma-
tions are most remarkable for the number of species.*

The occurrence of the Hemiptera-Homoptera in a
fossil state is much less frequent than that of the
Hemiptera-Heteroptera. According to some we find
their first appearance as the interesting Palceonfina
oolitica, which occurs in the Stoneslield roofing-
stone.

But whether or not this form has been rightly
classified, the Homoptera are clearly represented in
the insect limestones of Wiltshire and Dorsetshire.
In the Purbeck beds of these counties even the small
and frail bodies of the Aphididae have left their impres-
sions on the soft mud. These are accompanied by the
allied Homopterous families of the Cicadidee and

* Prof. Oswald Heer, ' Die Urwelt der Schweiz.,' 1865. Translated
by W. S. Dallas, 1876.

4 BRITISH APHIDES.

Cercopidse.* Apliis, therefore, liere for the first time
asserts its claims to the antiquity of its race.

Our present geological evidence will, therefore, lead
us to place the Hemiptera fourth in the order of birth
in primeval time, and thus to place the Diptera, the
Hymenoptera, and the Lepidoptera last on the list.
This sequence might, indeed, have been partly inferred,
if we take into account the connection shown by our
modern existent orders with phanerogamous plants.

The following may be assumed as the order in which
insects appeared, as set forth by known fossil remains.

1. Neuroptera. Devonian beds.

2. Orthoptera. Coal-measures.

3. Coleoptera. Carboniferous series.

4. Hemiptera.

,, Heteroptera. Permian and Lias.
,, Homoptera. Lower Oolite and

Purbeck. Aphis.

5. Diptera. Upper Oolite, Solen-

hofen limestone.

6. Hymenoptera. Solenhofen. Apis.

7. Lepidoptera. Solenhofen ? Sphinx.

Koch has described several fossil genera allied to
the minute IViysanura, which have been preserved.
Such being the case, we may not think it hopeless
that yet more evidence will turn up of the occurrence
of Aphides in ages long past, where climatal and other
conditions permitted.

The number of described living insects, Mr. Bentham
tells us, exceeds that of all known plants. Some ten
years ago Glerstaecker stated that the former exceeded
one hundred and sixty thousand. Mainly through the
pregnant hy]3othesis of Mr. Darwin, a considerable
stride has been made, as to deduction and correlation,
from materials supplied by these descriptions ; so that
now Entomologists less acutely may feel the charge

* Vide a compendious treatise by Mr. Herbert Goss on the ' Geological
Antiquity of Insects.' Van Voorst, 1880,

INTRODUCTION. 5

made against tliem some years ago, that tlieir " science
failed much in giving the origin, progress, migration,
mutual relation, struggle, decay, and final extinction of
species."

Still, when we step out from the observation of fact
into the region of sj^eculation, we must feel less cer-
tain of our footing. Many difficulties beset us as soon
as we leave the "irrefragable direct geological evidence."
If we ask what has been the order of insect evolution,
and the channel through which one form rose from
another, the answer is obscure.

In his Monograph of the Collembola and Thysanura,
Sir John Lubbock places before the reader in a succinct
form, considerations as to the probable parent stock of
Insecta, and he there so discusses the views of Fritz
Midler, Haeckel, Brauer, and Darwin, that it will be
right to touch but lightly upon it here.

Some have felt considerable difficult in conceiving
evolutionary passages from the powerful gnawing jaws
of the Orthoptera or Coleoptera, into the weak suctorial
organs of the Hemiptera or Lepidoptera. In the last
family it will be remembered that the larvee are man-
dibulate, and the images are hau stellate.

By adoption of Campodea (Thysanura) as an ances-
tral form, in which representative parts of jaws and
proboscis are present in the same insect. Sir J. Lubbock
thought much of this difficulty vanished.

Fritz Midler elects the wingless Orthoptera, or
Blattidge, amongst existing insects, as most .nearly
approaching to the ancient form; and further, bethinks i
that the metamorphosis of the Coleoptera and Lepi- I
do^^tera was of later origin. The imperfect meta- '
morphosis of the first insects, he thinks, is more like a
jDicture of an original mode of develoj)ment than the
perfect metamorphosis of beetles or moths. As to the
jjrobability of greater age in such an incomplete meta-
morphosis. Sir J. Lubbock quite agrees.

Haeckel thought that the four mandibulate orders
preceded the four sucking orders in time, but that an

6 BRITISH APHIDES.

insect something like Libellula was the type of the
original stock.

Sir J. Lubbock suggested, as a part solution of these
difficulties, that there is a distinction between develop-
mental and adaptive changes. Metamorphic variations,
indeed, do not necessarily proceed from the simple to
the complex, like ordinary growth of tissue; but
organs increase or become atrophied, according to the
wants of the insects attending their conversion into
pupae or images.

There can be little doubt that insects undergo
minute modification of form and organs throughout
their entire existence, if we except, perhaps, the
quiescent periods of chrysalis life. The action of tem-
perature, food, climate, starvation, or satiety, reacts
on the organism more completely perhaps, whilst the
animal is young, but developmental changes are
induced at each moult of skin ; and beyond and inter-
mediate to these stated periods, modified growth and
change of form are efi"ected. Thus, in the moultings of
Lepidoptera, sometliing more is accomplished than the
formation of a larger skin for the insect. Important
changes take place, which are interestingly shown by
the casting of the internal mucous membranes of the
tracheae.

The fact is significant that some beetles, like Meloae,
are born hexapod, and afterwards become apterous
maggots in the cells of bees, an economy discovered
some years ago by Newport. This has been considered
by some as a proof that the caterpillar form is adaptional
and not strictly developmental.

Whilst in the embryo of the Crustacean the limbs
come into view before the segmentation, in Insecta
the segments precede the formation of the legs. Fritz
Miiller, and Packard also, thought it probable that
perfect insects appeared before larvse or pupge, and
that the vermiform type is more recent. They con-
sidered the primitive form was nearly allied to our
grasshoppers (Orthoptera). Relative to this observa-

INTRODUCTION . 7

tion, N. Wagner points out that the vermiform larvoB
of certain small gnats have reproductive power to carry
on the series. In Diptera the larvae are footless grubs.

With reference to the mandibulate and haustellate
types of mouth, Sir J. Lubbock says " In Campodea a
type of animal occurs closely resembling certain larvas
which occur both in the mandibulate and suctorial
series of insects." On this account it is urged that
many difficulties would vanish by an adoption of Cam-
podea (Thysanura) as an ancestral type of Insecta.*

Conformity to conditions and occasional reversions
to ancestral tjrpes are now generally accepted biological
facts, and by their consideration we may expect a good
intellectual harvest. In the present volume some
remarkable examples of degradation are shown — cases
in which the visual organs are entirely aborted,! others
where they are in process of development during meta-
morphoses of the insect, and only show their complete-
ness in the imago. Similarly, the mouth-organs are
found to be aborted in the sexes of other species.
Once more we may find indications of a possible rever-
sion to an earlier tjrpe in some simpler forms of an
early age.

We may ask. Is the slightly endowed subterranean
Aphis more nearly allied to some presumed ancestral
form, but little differentiated; or should we consider it
to be a degradation from some higher genus like
Siphonophora or Drepanosiphon ? If we argue that
old forms are foreshadowed in embryology, the
Aphididas should come from a far-seeing stock; for eyes
appear in very early stages within the egg.

Thus, in Trama shall we trace, according to the
suggestions of Professors Lankester and Balfour, the
acquisition of eyes from a local deposit of pigment,
which through the stimulus of light and heat raises the

* ' Monograph of the Collembola,' Ray Society, 1873, p. 52.

t Examples of Aphides without eyes may be found in Trama, PI. CII,
fig. 6 ; in Schizoneura, PI. OVI, figs. 4 — 9 ; Pemphigus, PL CX, figs.
3—8 ; PI. CXI, fig. 8 ; PI. CXII, fig. 7. In other underground larva)
the eyes, if present, are very small.

8 BEITISH APHIDES.

outer cuticle into a crjstaline lens, with tlie subsequent
eangflionic elaboration of a retina, with its attendant
nerves, &c,, and throw all modification of form on the
adjacent surroundings ? *

A similar question arises, whether the tendency in
Aphis to show supplementary wing -veins is a sign of
development or the contrary. f Activity and swift-
ness in f3ightarenot necessarily connected with breadth
of wing. The nervous energy of the higher Hymeno-
ptera gives strength to their flying organs, which,
though relatively small, are capable of much loco-
motive power.

Again, shall we say that the lower Aphides are
degradations from Psylla, or improvements upon
Coccus ?

Probably Sir J. Lubbock would hesitate to regard
the Apterous Aphis as a larva, in the ordinary sense ;
and therefore its inactive form will not bring exception
to his supposition, that larvae which live in circum-
stances which call for no locomotion, have relapsed into
the condition of their far distant vermiform ancestors. :[:

In introducing these remarks upon these hypotheses,
we accept the conclusions simply as instalments, and
valuable contributions towards an abstruse and difiicult
question.

If " Phantasie " or theory be an element in the
demonstration of true science, she must ever be a
handmaid, but never a mistress. Some thinkers, like
Professors Tyndall and Lankester, have boldly acknow-
ledged that philosophers are, and ought to be, largely
occupied with speculation and imagination. The

* Examples in wticli the ti'ansparent corneal membrane is sliown to
be an expansion of the ectoderm or external cuticle may be seen in
PI. B, fig. 2; PL Xyil, fig. 4; PI. XXI, fig. 4; PI. XXII, figs. 4 and 5.
Some of these drawings show, also, how the optic nerve is in comunica-
tion with the oesophageal ganglion.

t The excess or defect in the veining of the cubitus may be seen in
PL XXXV, fig. 3; PL LVII, fig. 2; PL LXYI, fig. 2; and PL XOVI,
fig. 5.

X A slight tendency to the vermiform type, perhaps, may be traced
in the young underground inert larva of Pemphigus, see PI. CXII,
fig. U.

INTRODUCTION. 9

latter, indeed, has asserted that " biology is not the
less exact, our conclusions are no less accurate, because
they are oialj probably true."

However this may be, science which investigates
causation must to us be based upon likelihood ; and
therefore, so far, it partakes of a compromise. The
intelligent grouping of facts in one series, is uniformly
attended by another smaller series, which will not lend
themselves to the conception of the law deducible from
the first grouping. But no one will loyally put aside
that law, if it be reasonable, on account of exceptions
to it ; but receive it as an instalment and vantage-
ground gained from the land of ignorance.

If a master-mind rises afterwards and regroups
these facts under another law, so as to eliminate more
exceptions, the student who would ascertain the causes
of things, will give in his adherence to the new line of
thought, even though it be like " Phantasie." The
system of Ptolemy thus has given place to that of
Copernicus ; phlogiston to the atom of Dalton, which
again suffers modification in the modern atomicity of
Gerhardt, Graham, Wurtz, or Brodie.

After all, a knowledge of the fundamental cause of
variation is the high desideratum of the biologist.
How and why certain cells should have special func-
tions of segregation for elaborating different organs we
know not, and at present we see but little chance of
knowing. Certain cells have been regarded as vehicles
containing groups of physiological units, ready to obey
their proclivity towards the structural arrangements of
the species they belong to. This appears to accord
with the views of Herbert Spencer, who assumes
" units of protoplasm lower in degree than the visible
cell-units of plastids, and which may be regarded as in
a polar condition."

Prof. Ray Lankester remarks that modified force-
centres may become further modified in each genera-
tion, and this might be made to fit in with Mr. Darwin's
theory of Pangenesis. The subject, however, is beset

10 BEITISH APHIDES.

with difficulties, and we can hardly be said to have in
possession materials to do more than theorise. Some
inscrutable force is connected with the secret of life,
with its metamorphic powers, and its attributes of
irritability, assimilation, reproduction, and final death.

Mr. A. Wallace would seem desirous to cut the knot of
this difficulty, by stating " that variation is an ultimate
fact of nature, which wants no further explanation
than that we cannot even conceive it to be otherwise."

As motion in nature is the universal law, and even
" the stars fixed for ever " have their tendency some-
where, so doubtless life and spirit are no exceptions to
this rule, but have ever an upward progress, or a
miserable degeneracy.

But dogmatism ill becomes the student. Montaigne
quotes :

" Nee me pudet ut istos, fateri nescire, quod nesciam ;"

and, again, a great mind has said :

" Doubt nestles at the root of TrutH."

" Nasce per quello a guisa de rampoUo
Apple del vero 11 dubblo. . ."*

" Honest doubt is the deepest spring of honest faith. "f

Nevertheless, we may yet founder upon a one-sided
agnosticism — the pride which apes humility.

* Dante, ' Del Paradiso,' Cant, iv, 1. 130.

t Prof. Max Miiller, ' Lectures in the Chapterhouse of Westminster.'

SYNOPSIS OF BRITISH APHIDID^.

I.

Aphidinse

fUpper wing with twice-
I forked cubitus; under
•{ wing with two oblique )■ 16. Callipterus.
I veins; antennae 7-joint- j
l_ ed . . . .J

Lachnince

f Upper wing with twice-
I forked cubitus ; under
■{ wing with two oblique «
I veins; antennae 6-joint-
ledL ....

'17. Pterocallis.

18. Phyllaphis.

19. Ptychodes.

20. Lachnus.

21. Stomaphis.

22. Paracletus.

23. Trama.

24. Dryobius.

II.

{Cubitus once forked ;
lower wings with 2
oblique veins

i}25.

Schizoneura.

III.

Pemphiginse

rCubitus not forked ; (f„- ^^f'V^'S^^s.
' lower wings with 1 oi' ) ^7. Tetraneura,
2 oblique leins . ./ yoneura.
^ V. Toxoptera.

Cubitus once forked ;
lower wing with 1
. oblique vein

j-y C Upper wing with only 3

^1 ' • „ •< veins; under wing

Chermesmse i - - ..' . =>

only 3 ^
g with >

Thelaxes,

Chermes.
Phylloxera.

(. 1 oblique vein

Rhizlbiin. ] W-g^<l f--^ -^— { Sfs'

N.B. The genera in italics are not, it is believed, represented by
British species.

P^

o

Vol. m.

12 BBITISH APHIDES.

Family —APHIDIDiE .

Tribe-APHIDINiE.

Genus XYI.— CALLIPTERUS,* Koch.

ZlEELAUS. FaIRWING. GaY-LOUSE.

Hostrum stout, sliort ; does not reach to the second
cox9e.

AntennaB very long, often tipped with black ; third
joint much the longest. Seventh joint variable in
length, but rarely less than the sixth. In the winged
females sometimes it attains to twice the length of the
sixth.

Head large, vertex flat. Frontal tubercles none.

Cornicles very short.

Legs moderately long ; longest in the males.

Wings generally ample, iridescent, usually clouded
with pigment at the extremities of the veins. Stig-
mata long. Stigmatic cells trapezoidal.

Abdomen : in some species the apterous females
are hirsute. The last abdominal ring is provided with
two anal valves or papillae.

In the above description I assume that Gallipterus
possesses seven antennal joints, which some of the
species ranged by Koch under his genus do not possess.

Passerini, on the other hand, restricts this genus to
the two walnut-feeding Aphides, and groups it under
the Lachnince.i

The genus Galliptenis, as its name imports, includes
some of the most elegant forms of the Aphidinse.
From their bright and lively colouring, they have

* From KaWos, beautiful ; irrfpov, a wing,
t ' Aphididee Italicse.' p. QQ.

OALLIPTERUS. 13

received the names of Zierlause in Germany, and Gray-
louse in America.

The generic characters are sufficiently distinct ; but
nevertheless on account of the recurring difficulty, as
to what constitutes a true articulation of the antenna,
these insects have been variously placed, with or out-
side of the Lachninge. Amongst the species named by
Koch and Passerini, some have the antennal joint
more than twice the length of the preceding, whilst in
others it by no means equals the same. I consider, in
accordance with the American systematists Riley,
Monell,* and Thomas,! that these longer terminals
have as much right to be considered true articulations,
as those we find in Chaitophorus ; and this, coupled
with the extreme shortness of the rostrum, and the
different habits of life, I think quite justifies us in the
separation of CaUijoterus from the group to which
Lachnus belongs.

Although the dark cloudings which border the veins
of the upper wings of these insects are not to be found
in all the species — and, indeed, are not peculiar to
CalUpteruSj yet they give an elegant and marked cha-
racter to the Aphis, which should not be disregarded
in the notes of their diagnosis.

As a rule, their bodies are light in weight, and
prettily barred with rich brown on a yellow or greenish
ground colour. The wings are voluminous, and pos-
sess the same number of veins and furcations as in all
the genera previously described.

The Calli2)teri nowhere form large companies or
swarms like Aphis proper, but aff"ect a more solitary
habit of life, only two or three being usually found
under one leaf. The hazel Aphis, however, will some-
times congregate to fifty or more under a single leaf.
These, probably, are the progeny of a single parent,
often to be found amongst them.

* 'Notes on Aphidida3 of the United States.' Riley and Monell,
1879. P. 28, et seq.

t ' Eighth Report on Noxious and Beneficial Insects of the State of
Illinois.' By Prof. Cyrus Thomas. P. 109.

14 BRITISH APHIDES.

I do not see characters sufficiently distinct between
Myzocallis of Passerini and CalliiJterus of Koch, to
necessitate a separate genus. I have, therefore, united
these insects under one head.

Callipteeus betulaeius, Kalt.^ Plate LXXXVII.

Aphis tuderculata, Heyden (?).
„ antennata, Kalt. (?).
„ betulcB, Walk.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0-090xO-030 2-27xO-76.

Length of antenna O'llO 2*80.

)}

cornicles 0-005 0-12.

Linear, wholly green, slightly ochreous in the
anterior parts, shining, very rugose from the presence
of tubercles, each of which is furnished with a tuft of
capital hairs as in Chaitophorus. Front hairy ; eyes
red ; antennae very long, seventh joint twice as long as
the sixth. Cornicles short and trumpet-like. Tail
obtuse and small.

Winged viviparous female.

Inch.

Millimetres.

Expanse of wings

0-240

6-09.

Size of body

0-075x0025

1-89 X 0-62.

Length of antennae

0-140.

3-60.

cornicles

0-005

0-12.

Linear, wholly bright green, not so pilose as the
apterous larva. Antennse long, and ringed with
brown. Seventh joint at least twice the length of the
sixth.

Abdomen edged with small tubercles. Nectaries
and tail green. Legs long and green. Wings mode-
rate. Points rather rounded. S^tigma^ cubitus, and

OALLIPTERUS BETULICOLA. 16

other veins pale green. Body and legs pilose, but not
tufted witli cotton. The wing veins are not expanded
or clouded at their tips, as in G. hetulicola. A reference
to the plates will show that the venation also is dif-
ferently disposed in these insects, both of which, how-
ever, feed on the same tree.

Apterous oviparous female.

Inch. Millimetres.

Size of body 0-165 X 0-075 4-18 X 1-89.

Length of antennae 0-140 3-60.

„ cornicles 0*007 0-17.

Long and fusiform. Abdomen large and pointed ;
the last rings dilated much as in the genus Drepanosi-
plmm. Colour amber-brown or darker, with six or
seven interrupted rusty-brown cross-bars, the third,
fourth, fifth, and sixth of which are furnished with
round, whitish tubercles. Antennae and legs stout,
long, and green. Tarsi dark brown. Eyes red.

The winged male is much like the winged viviparous
female. The perfect sexes may be captured in
October, at which time the female commences to ovi-
posit on the common birch and on the weeping variety
of the same tree.

This fine insect is more common than G. hetulicola.
I have repeatedly taken it from August to October
near Chichester, and on the birches round Haslemere
in Surrey.

Callipterus BETULICOLA, Kalt. (?). Plate LXXXYIII,

figs. 1—3.

Aphis behilicolay Kalt. (?), Walk.
Gallipterus betulce, Koch.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0-110x0-035 2-80x0-88.

16 BEITISH APHIDES.

Inch. Millimetres,

Lengtli of antennge 0*120 3*04.

)}

cornicles 0'005 0-12.

Colour yellowisli green. Form long oval, apex
pointed. Eyes fine red. Antennse very long, longer
tlian tlie body, and ringed with black. Cornicles very
short, body setose. Cauda inconspicuous.

Winged viviparous female.

Incli. Millimetres.

Expanse of wings 0*380 9*64.

Size of body 0*110 X 0*030 2*80 X 0*76.

Length of antennge 0*180 4*56.

„ cornicles 0*005 0*12.

Long oval, almost fusiform. Abdominal apex acute.
General colour bright green. Head with an obscure
linear brown patch, and obvious stemmata. An-
tennge very long, ringed with black at the joints, and
often decked with cottony tufts. The seventh joint
nearly equal to the sixth. Thoracic tubercles and
scutellum warm brown. The antennge rise from
obscure frontal tubercles. Abdomen mottled green,
more or less dusted with fibrous matter ; lateral edges
furnished with minute warts. Cornicles about twice
as long as broad. Cauda small, pointed, and hairy.
Legs very long, green, with black knees and tarsi;
irregularly tufted. Sternum with a dark squarish
patch. Rostrum reaches to the second coxge. Wings
slightly fuscous, long, and narrow, pointed at their
apices ; costa and stigma pale green ; other veins
brown and clouded at their ends. The pupa is coloured
much like the larva.

This fine insect locates itself in small companies at
the summits of the shoots of the hirch Betula alha. It
is very active and runs just before taking wing. It
has some resemblance to B. platanoides . Though
perhaps not very plentiful anywhere, it may be taken

CALLIPTEEUS CORYLI. 17

at Critchmere and other localities near Haslemere, from
April to July.

This insect shows considerable variation as to tint
and markings. Walker describes several such in the
* Ann. of Natural History.' He there notices the
oviparous female and the winged male as coupling
during September and October.

Several birch-inhabiting Callipteri have been de-
scribed by American authors. Galli])terus betulcecolens
of Riley and MonelZhas much in common with ApJiis
hetuUcola, Kalt. ; Callaphis hetulella of Walsh, is diffi-
cult to identify ; but failing other reasons, should not
be separated from Gallipterus on account of any acci-
dental absence of a stigmatic vein. This vein seems
to be the most persistent wing vein in all Aphides. In
America, Prof. Cyrus Thomas shows that these insects
range from the Eastern coast throughout Mississippi
and Illinois States. The last author notices that the
stigmatic veins are obsolete at their bases, which
peculiarity I have not remarked in the British species.

Callipterus coeyli, Goetze. Plate LXXXVIII, figs.

4-7.

Aphis coryli, Goetze, Sir 0. Mosley, Kalt :
Gallipteriis coryli, Koch.
Myzocallis coryli, Pass.

Apterous viviparous female.

Inch, Millimetres.

Size of body 0'070xO-030 1-77X'076.

Length of antennse 0'050 1*27

j>

cornicles 0-005 012

Smaller than G. carpini, which it somewhat re-
sembles. Almost white and transparent, shining ; whole
body tuberculate and studded with capitate bristles.
Eyes red. Antennae shorter than the body, ringed

18 BRITISH APHIDES.

with black. Nectaries pale. Tail large and obtuse.
Legs short.

The Pupa.

Less linear than the pupa of C. carpini, which Pas-
serini considers to be identical with C. coryli.

Winged viviparous female.

Incli. Millimetres.

Expanse of wings 0'265 6'72.

Size of body 0-065 X 0'025 1-64 X 0-62.

Length of antennae 0*060 1*52.

„ cornicles 0-007 0*17.

Wholly pale yellow, or else citron yellow. Head
rather broad. Vertex prominent. Cornicles yellow.
Legs short. Wings hyaline and not clouded with
brown. Insertions, stigmata, and veins yellowish green.

Sometimes this little Aphis swarms by hundreds
under the leaves of the hazel, Gorylus avellana; forty
or more being crowded on a single leaf. At other
times the Aphis shows a more solitary habit. Kalten-
bach says it affects also Carpinus hetulus and even
Fraxhius excelsior. Their activity appears to be much
less than that shown by the Gallipteriis of the birch.

Walker says that this nut-Aphis is much preyed on
by the little Myina flava, which insect is also parasitic
on G. quercus and perhaps on Pterocallis tilice.

The oviparous female greatly resembles the vivi-
parous female, but the abdominal apex has a squarish
termination, and the last ring is furnished with well-
marked geneto-anal valves. Several specimens were
secured in the month of November, and they contained
from three to five forward ova. Most of the hazel-
tree leaves had then fallen, and the rest were dry and
yellow. Probably the eggs, when mature, are deposited
in crevices of the bark. Nevertheless, I have failed
to find them in such places.

CALLIPTERUS CARPINI. 19

Oallipterus oaepini, Koch. Plate LXXXIX.
Aphis coryli, Kalt. (?).

Apterous viviparous female.

Inoli. Millimetres.

Size of body 0*090 X 0-045 2-27xl'13.

Length of antennjB 0'085 2"14.

„ cornicles 0*007 0-17.

Large, wholly pale yellow or greenish ; resembles
Gallipterus coryli, but its habits are diflPerent and pro-
portions unlike. Body covered with capitate hairs.
Antennge shorter than the body. Very active, running
from one side of the leaf to the other when disturbed ;
several individuals congregate on the same leaf of
Betula tremula, and, according to Koch, also on Car-
pinus hetulus. Common near Chichester from June to
October.

The Piipa.

Long oval, attenuated behind. Head broad, vertex
pilose. Body pale shining green, covered with capitate
hairs, but some specimens are smoother than others.
Antennse as long or longer than the body, and ringed
with black ; the seventh joint twice as long as the
sixth. Rostrum does not reach to the second coxse.
Cornicles very small, generally black at the tips. Legs
and wing-cases pale green.

Winged viviparous female.

Inch. Millimetres.

Expanse of wings 0-380 9-64.

Size of body 0-120x0-040 3-04x1-01.

Length of antennse 0-140 3* 55.

cornicles 0-002 -05.

Large, bright green, slightly tuberculate. Rather
mealy. Head and prothorax with a dull brown spot.
Antenna brown, long ; seventh joint only equals the

20 BRITISH APHIDES.

lengtli of the sixth, but is somewhat variable in length.
Thoracic lobes brown. Abdomen slightly ringed.
Nectaries very small. Cauda yellow and rather large.
Legs moderately long. Wings pointed. Cubitus and
stigma yellow. Other veins pale brown and clouded
at their tips. Often the cubital vein does not touch
the cubitus.

Apterous oviparous female,

luch. Millimetres.

Size of body O-lOOxO-050 2-54xl-27.

Length of antennee 0*040 1*01.

Less linear than the pupal form. Bright yellow
tinged with crimson. A crescental brown mark on
the head carried over the thorax. Abdomen with a
broad brown bar followed by three or more other inter-
rupted bars, and a very broad pa.tch of the same colour
on the lower dorsum. Tail elongated into a kind of ovi-
positor and tipped with bristles. AntennjB and necta-
ries very short. The seventh joint of the latter reduced
almost to a " nail."

Apterous male.

Very small. Bright yellow, or pale brick-red, with
a red dorsal stripe crossed by seven or more transverse
stripes of the same colour, thus giving a gay appear-
ance to the insect. These males are not uncommon
in early October, when they mix with the oviparous
forms. Their bodies are internally crowded with
oily globules, which in great measure furnish the
general ground colour of the insects, pigment being
alone deposited in the fascial marks. Dissection clearly
proved the sex of these specimens.

Winged male.

These insects are more brilliant in colour and band-
ing than the other forms. Grround colour fine yellow.

CALLIPTERUS QUEROUS. 21

head, thorax, and abdomen banded and spotted with
rich brown. The antennse are longer, and the stigmata
are more of a grey shade than with the females.

This species furnishes one more example of the
dimoTjpliism of the males, and points out the plasticity
of this insect family under the varying action of local
surroundings.

At present we are ignorant whether or no there be
any modification of form in the insects hatched from
the broods of these different paternities. If there
should be any difference, the circumstance would have
considerable interest with the morphologist.

Calliptekus quercus, Kalt.i Plate XC.

Aphis quercus, Kalt., Walk., Ratz.

GaUlpterus quercus, Koch.
Myzocallis quercus, Pass.

Apterous oviparous female.

Inch. Millimetres.

Size of body 0*080 X 0'040 2-02 X I'Ol.

Length of antennae 0*060 1'52.

„ cornicles very small. „

Flat, oval, pale green or yellow, some examples are
almost colourless ; front bristly. Antennae not so long
as the body ; pale, ringed with brown. Eyes brown
or reddish. Abdomen with two rows of brownish trans-
verse dashes, and six or more tubercles with capitate
bristles on each lateral edge. Cornicles green and very
short.

Pupa.

Paler than the larva. Wing-cases and legs pale
yellow-green. More hirsute than the last-described
form.

22 BRITISH APHIDES.

Winged viviparous female.

Incli. Millimetres.

Expanse 0*260 6-60.

Size of body O'OOOxO'OSO 2-27 X 0-76.

Length of antennae 0"085 2"14.
„ cornicles very small.

Pale green or light yellow. Antennae at least equal
in length to the body, ringed with black. Seventh
joint about equal to the sixth. Nectaries green, some-
times tipped with brown. Abdomen occasionally
obscurely barred with brown, and furnished on the
dorsum with six pointed tubercles disposed in two
rows, unobserved by Koch. Rostrum very short, not
reaching to the second coxse.

This species is common on the sessile oak, Quercus
sessiliflora from spring to October. I have taken it
feeding also on QuercAis ilex ; and Walker observed it
on the American chestnut, Gastanea pumila. They
form small companies of four or six under the same
leaf, and they intermix with the next species, GalUjjte-
rus querceus, and Thelaxes (Facuna) dryophlla.

The young are nearly white or colourless, with eyes
more or less spotted ; by age these last organs become
red.

Apterous oviparous female.

Inch. Millimetres.

Size of body O'OSO x 0*045 2*02 X 1-13.

Fine yellow or salmon-colour, with greenish dorsal
stains, which dilate near the tail. Body ringed, tuber-
culate, and hirsute. Eyes spotted with brown.
Geneto-anal rings obtuse and rounded. Rostrum as
with the other forms.

Taken at the end of November whilst ovipositing
on a dry leaf. They, however, will oviposit also in the
middle of October.

As these leaves fall to the ground, it is probable that

OALLIPTERUS QUERCUS. 23

the eggs of some species of Aphides pass the winter
on or under the ground, and the young Aphis com-
mences active life at the return of spring warmth as
the leaves push forth.

It has been before noticed that the only memoir
on the reproduction and morphology of Aphides
in English, which is worthy of the name of a scien-
tific treatise, is from the pen of Professor Huxley.
In this elaborate paper Professor Huxley points out
the significance of the ovarian tubes and the adjuncts
which appertain to the perfectly-sexed female; and sub-
sequently he shows the representatives of these organs
in the chambers of the pseudovaiia, &c., in the vivipa-
rous female. To illustrate these latter details, Prof.
Huxley selected for experiment the common species
Ai^liis pelargo7iii (Siphonojjhora) , and there can be no
reasonable doubt of the identity of the species he dis-
sected. The same certainty, however, does not appear
to attach to the second species chosen to illustrate the
evoli^ion of the true ovum.

Perhaps some knowledge as a specialist is required
at once to fix on the salient characters of a particular
form of Aphis, and thus there is little cause for wonder
that some obscurity attaches to the specific name
assigned in this paper by Huxley to the oviparous
females he examined.

At the end of his memoir Professor Huxley, whilst
expressing his belief that the Aphides he obtained from
the oak were Vacuna drijophila of Schrank, does not
speak with complete confidence, but states '' that his
insect had certainly seven joints to the antennge."
Yet Vacuna certainly has but six, even if we count the
nail-like terminal process as one. Again, in the diagnosis
of the species, it is stated that the body is covered
with setose tubercles, that it has trumpet-mouthed
syphons, and that the abdomen is ornamented with
transverse rows of dark spots, each row representing a
segment. These characters certainly better accord
with those of the genus Callipterus than with those of

24 BEITISH APHIDES,

Vacima. Professor Huxley has kindly compared two
of his own pencil sketches with drawings I have made of
these two genera, and with the sincerity of a truth-
seeker he writes that " The former appear to me to
agree with your CalUpterus quercus more nearly than
with any other species among those you have figured."
I may say also that these sketches were kindly for-
warded to me, and that to my mind they had all the
peculiarities attaching to CalUpterus.

A settlement of this question is of the more import-
ance, since the genus Facuiia^ must be considered
somewhat removed from the typical Aphis, and we
might therefore, perhaps, expect a somewhat varied
parallelism between the morphology of the perfect and
imperfect sexes of the genera Siplionoplioray Galli-
pteruSi and Vaoufia.i

Oallipterus QUERCEUS, Kalt., Plate XOI, figs. 1 — 4.

Aphis querceaf Kalt., Ratz., "Walk. (?).
Myzocallis queyxea, Pass.

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-070xO-035 1-77X0-88.

Length of antennas 0*060 1'52.

„ cornicles very small.

Smaller than C. quercus. Variable as to its mark-
ings. General colour darkish green mottled with
brighter green. Cornicles tipped with black, about
the length of the body, and tinged with black. Eyes
usually spotted with red.

* The genus Thelaxes of Westwood lias prioi'ity over Vacuna of
Heyden, but I have retained the latter name here as it appears in
Professor Huxley's papers.

t Huxley "On the Morphology of Aphis," 'Trans, Linn. f5oc.,\vol.
xxii, part 3.

CALLIPTERUS QUEECEUS. 25

Yae. I. — Winged viviijarous female.

Expanse of wings
Size of body
Length of antenna

Inch.

0-180
0-070x0-025

0-080

Millimetres.

4-56.

1-77x0-62.

2-02.

„ cornicles

0-002

0-05.

Yery small. Bright green with pale thoracic lobes.
Head and prothorax very large. Eyes large, bright red.
Antennae nearly white, with dark spots at the joints.
Seventh joint rather longer than the sixth. Abdomen
mottled with paler green. The third ring has two
pointed dorsal processes. Legs whitish and short.
Cornicles very small, and tipped with black. Wings
short and rounded at the tips. Costa much curved,
as also is the cubitus. Cubital vein forms in curvature
almost the segment of a circle ; furcations almost
equally long. Cauda very obtuse.

Yae. IL — Possibly the produce of an earher birth.

Much larger. Expanse of wings 0-240 inch.
Colour similar to the foregoing, but the thoracic lobes
are olive-green, and the abdomen is tinged with orange.
Seven or more crescentic bands are ranged down the
dorsum. Wings longer than in the preceding variety,
and not quite so much curved as to the costa. Eyes
pink, spotted with red.

Winged male.

Inch. Millimetres.

Expanse of wings 0-210 5-35

Size of body 0-060 X 0-020 1-52 X O'SO

Length of antennae 0*080 2«02
,, cornicles very small

Small, cinereous green. Head and thorax very
broad. AntennjB and legs ashy. Wings rather long,
greyish. Cubitus and stigma sooty brown. Yeins black,
and clouded slightly at their ajDices. November.

26 i3RITISfl APHIDES.

This species seems to vary considerably as to size
and form, so much so, as to leave me in some doubt as
to whether the insects I now describe are really iden-
tical with those of Kaltenbach and Walker. Kalten-
bach mentions the occurrence of a green tubercle which
is furcate on the second ring (abdominal ?), and that
two or three tubercles are to be found on the lateral
edges. Neither of these characters are given by
Walker, and I do not find them in my specimens as
thus set forth.

Taken on Quercus robur at Weycombe and at Wan-
stead, Essex. According to Passerini the Italian
insects are all more or less clothed with down.

Oallipteeus CASTANET, BucMon. Plate XCI, figs. 5 — 9.
Callipterus castanew. Pitch (?).

Apterous viviparous female.

Inch. Millimetres.

Size of body 0"060x 0=035 1-52 X 0-88.

Length of antennsB 0'035 0*88.

„ cornicles 0-002 0-05.

Body ovate, somewhat flat, pale green or yellowish.
Front convex, and furnished with bristles. Head and
thorax broad. Two rows of dark brown or greyish
spots, eight or nine in number, ranged down the dorsum,
which rows are continued through the thorax. Four
or five similar marks occur near the stomata. An-
tennse pale green, with black articulations. Eyes black.
Tail rounded and hairy. Eostrum very short. The
whole body covered with capitate hairs.

This insect is somewhat solitary in habit. It is
plentiful at Haslemere in the copses of the sweet chest-
nut, Castanea vesca, from early May to December.
Towards the end of Autumn the brown bandings on
the abdomen have a tendency to increase in breadth
and so they make the insect darker in tint.

OALLIPTERtJS CASTANET. 27

The Pupa.

Bright yellow, with very few brown markings ; body
very pilose. Shape rather globose.

Winged viviparous female.

Inch. Millimetres,

Expanse of wings 0*200 6'08.

Size of body 0*055 X 0-025 1-39 X 0-62.

Length of antennse 0*060 1*52.

cornicles 0*002 0*05.

This is an elegant little species. Colour bright citron
yellow, prettily marked with brown squarish spots.
Head and thorax broad. Front convex, marked by a
fine band, and this is followed by a series of fine dashes
through the prothorax. Three longitudinal dashes
mark the thoracic tubercles. Abdomen oval, smooth,
and ornamented with four rows of horizontal oblong
spots ranged down the dorsum. The number of spots,
however, is not abundant. Cornicles very short and
brown. Legs moderately long, hairy. Antenna!
third joint tuberculate, the seventh joint equal to the
sixth. "Wings rounded, with yellow insertions, cubitus,
and other veins. Stigmata pale brownish, with a
darker clouding at the anterior and posterior angles.
Veins expanded at their apices into brown cloudings.
Eyes in the adults bright red, but in the freshly emerged
images they are spotted.

Apterous oviparous female.

Much liketheform and colour of the last, but the dark
bandings cover more of the insect. Tail and nectaries
pale green. On December 4th a specimen was confined
by a bag of gauze to the twig of chestnut on which
she was located. After she had laid a certain number
of eggs she was dissected under some weak syrup,
and as many as thirteen eggs were obtained from
her, all of which were in a forward state of maturity.

VOL. III. 3

2S BRITISH APHIDES.

The lowest temperature of the previous night was
21° Fahr. The naturally extruded eggs were black,
but they were not of a true oval form, being attenuated
at one end, and deeply corrugated. Those within the
abdomen were of a normal shape. The collateral
glands, close to the vaginal orifice, were well made out
under the microscope ; also dissection showed a well-
marked expansion of the alimentary canal into a
distinct but somewhat small stomach. The presence
of this organ shows that the perfect sexes therefore
are capable of taking nourishment, which is not the
case in some species of Aphis lower in the scale of
development.

This appears to be a species hitherto undescribed in
Europe.

In America, however. Fitch has described, under the
name of the " Chestnut Gay-louse," a sulphur-yellow
Aphis, which may prove to be identical with the above
British species. The measurements (0"09 inch) and
wing cloudings differ, however, and there are other
minor points, which make it unsafe to decide the point
without inspection of the continental species. I place
Fitch's insect, therefore, as a doubtful but probable
synonym.

I.

APHIDIN^.

• SECTION

LACHNIN^, Pass.

UPPER WING WITH A BIFURCATE CUBITUS.
LOWER WING WITH TWO OBLIQUE VEINS.
ANTENNA SEX-ARTICULATE.

LACHNINiE.

This section includes a number of insects, whicli
show sufficient peculiarities of structure to allow
a definite separation from the foregoing Aphidinae.
The few genera comprised in this group are perhaps
best typified by Illiger's old genus Laehnus, which fur-
nishes three very fine characteristic species, all of
which are inhabitants of the oak-tree.

As to the wing-venation, the Lachnince do not much
depart from the species hitherto described in this
Monograph, but the positions and the curvatures of
the veins somewhat difi'er. The forking of the cubital
vein still obtains, but in the less developed species there
seems to be a tendency to the suppression of the
second oblique vein of the lower wings. This occurs
only in abnormal specimens.

The antennae are reduced in length, and this is in
great measure caused by the loss of the seventh joint,
which is reduced to the condition of an elongated
button or papilla.

PTEEOCALLIS ALNI. 31

Genus XYII.-^PTEHOOALLIS,* Passermi.

Eostrum stout and short, scarcely reaching beyond
the first coxae.

Antennae shorter than in Callipterus, six-jointed,
the usual seventh joint being represented by a sudden
thinning off of the extremity of the sixth.

Cornicles small and tubercular.

Wings rather shorter than in Callipterus. The
membrane sometimes clouded or brocaded.

Passerini gives as a character, " Alarum anteriorum
venaB obliquse apice in maculam fuscam amplam-
triangulam dilatatge."

Pteeocallis ALNI, Fabr. Plate XCII, figs. 1- — 4.

AjjJiis alni, Fabr., De Geer, Kirby and Spence,

Kalt., Walk.
Callipterus alni, Koch.
Pterocallis aim, Pass.

A'pterous viviparous female.

Inch.

Millimeti-es,

Size of body

080x0035

2-02x0-88

Length of antennae

0-050

1-27.

„ cornicles

0-005

0-12.

Oval, transparent, pale green ; blotched at the sides
and across the dorsum with dark green. Body some-
times wholly pale green and without blotches. Eyes
warm brown. Antennae whitish, with the tips of the
last three joints black. Abdomen carinated and
covered with tubercles, from each of which tufts of
hair rise. Cauda obtuse. Cornicles very small, green
in the young individuals, but tipped with black in the

* From iTTtpov, a wing, and kuWos, beautiful.

32 BEITISH APHIDES.

adults. Tarsi black. Rostrum very short, reacliing
only to the first coxse.

This insect, as a larva, is very like Gallipterus coryli,
but the hairs are non-capitate. Taken on the Alder,
Alnus glutinosa, at Haslemere and at Edgware towards
the end of May.

Winged viviparoiis female.

Inch. Millimetres.

Expanse of wings 0'230 5-84.

Size of body 0070X0-030 i-77x0'76.

Length of antennse 0*090 2*27.

„ cornicles O'OOS 0-12.

Small, wholly bluish or yellowish green. Eyes
brown. Antenna long and ringed with black. Sixth
and rudimentary seventh joints very short ; together
not equal to the fifth. Abdomen slightly tuberculose.
Nectaries very small. Legs pale green and short.
Rostrum very short, rather beyond the first coxse.
Wings moderately long. Cubitus and costa green.
Stigmata grey. Veins very slender, with a tendency
to expand at their apices into a cloudiness. Habits
active, but rather solitary ; one, or two insects at most,
being found under a single leaf. The winged female
occurs at the end of June. Two anal papilla (after-
lappchen) are obvious.

Pterooallis juglandicola, Kalt.j Plate XOII, figs. 6-— 8.

Lachnus juglandicola, Kalt.
Aphis juglandicola, Walk.
Gallipterus juglandicola, Koch., Pass.

Apt&t'ous viviparous female.

Inch. Millimetres.

Size of body 0-055 X 0'030 1-39 x 076.

Length of antennae 0-020 0-50.

„ cornicles 0*002 0-05.

PTEROOALLIS JUGLANDICOLA 38

Small, oval, pale greenish or bluisli yellow. Eyes
red. Body finely setose ; hairs capitate. Young spe-
cimens are nearly divested of all markings, but the
adults have two longitudinal rows of black dorsal
spots. Eostrum very short, reaching just beyond the
first cox£e.

Pupa,

Inch. Millimetres.

Size of body 0'065 X 0-032 1-64 X 0-80.

Length of antenni» 0*060 1*52.

Considerably larger than the foregoing insect.
Colour yellow, green, and ferruginous. Wing-cases
pale bluish. Abdomen with four rows of black spots.
Koch states that the antennae are shorter than those
possessed by the apterous female. The example I
figure difi'ers in this respect.

Winged viviparous female.

Inch.

Millimetres.

Expanse of wings

0-180

4-56.

Size of body

0-065X0-025

1-64x0-62.

Length of antennge

0-035

0-88.

„ cornicles

0-002

0-05.

Wholly bright yellow or orange colour. Thoracic
lobes rather orange-brown. Antenna short, tips of
the joints black. Rudimentary seventh joint about
half the length of the sixth.* Abdomen nearly trans-
parent, usually showing the internal trachese. Legs
and nectaries wholly yellow. Wings moderately long ;
the costa and cubitus somewhat curved inwards. All
the veins, the insertions, and stigmata fine yellow.
The anal ring is furnished with two papillae, which are
crenated.

* On account of the size of the seventh anteimul joint possibly this
species might be ranged under Callipterus ; I leave it, JiQwever, wherQ
Passerini has placed it.

34 BRITISH APHIDES.

Apterous oviparous female.

Hirsute, greenisli yellow, with two involuted black
marks on the thoracic region, and three black con-
fluent bands on the abdomen. The antennge are short
and ringed with black. Legs green, with isolated black
spots at the tips of the femora. Cauda rounded. The
example figured was captured at the end of July, and
even at that early season it contained two large eggs.
Walker obtained females with four eggs. The same
observer describes the male as winged, like the vivi-
parous female, but more slender of form.

This species feeds, and close to the rib-veins, on the
under surfaces of the leaves of the walnut tree, Juglans
regia. It occurs from May to October, but it is not
common.

Pterocallis TiLiiE, Linn., Plate XOIII.

Aphis tilice, Linn., Eeaumur (?),De Geer, Schr., Walk.
Callipterus tilice, Koch.
Pterocallis tilice, Pass.

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-080 X 0-035 2-02 X 088.

Length of antennse 0*060 1-52.

cornicles 0-005 0-12.

Long oval, shining green or yellowish. Head and
prothorax black. Eyes red. Thorax with a large
square spot flanked on each side by another spot.
Abdomen domed and crossed by numerous black bands.
Carina with spots corresponding to the same. An-
tennae, tail, and legs green ; the former ringed with
black. A distinct and fine line cuts across the occi-
pital and the five or six abdominal fasciae. Some
individuals are almost uniform in colour and without
bands 5

PTBROCALLIS TILI^. 35

Winged viviparous female.

Incli. Millimetres.

Expanse of wings 0-280 7*10.

Size of body O'lOO X 0-025 2-54 X 0-62.

Length of antennse 0*080 2-02.

„ cornicles 0-002 0-05.

Bright yellow. Two fine waving black lines run
behind the eyes, which are continued down each side
of the prothorax. Two irregular lines mark the tho-
racic lobes. Five black dots occur on each side of the
dorsum. AntennsB yellow, with black rings. Tarsi
and hind femora black. Geneto-anal plates conspi-
cuous. Wings ample ; insertions, cubitus, and stig-
mata dark grey. Other veins grey, and broadly
clouded at their apices. The stigma, which is large,
has a dark stain at its inner margin. The rostrum is
very short, and hardly exceeds the length of the head.

Pupa.

Rich lemon-yellow, sometimes pale green. Wing-
cases greenish. Antennae as long as the body.

»

Winged male.

Inch. Millimetres.

Expanse of wings 0*260 6*62.

Size of body 0*050 X 0-030 1-27 X 0*76.

Length of antennae 0-090 2*27.

Body small in proportion to the voluminous wings.
Not unlike the female in colour. Head streaked with
black. Antennae very long and ringed ; the third
joint much tuberculate. Eyes bright red ; stemmata
prominent and green. Dorsum with two rows of
black spots. Wings prettily clouded with grey.
Appears in September and October.

Walker states that this Aphis, like some others, has
a supplementary wingless male. He describes the
oviparous females as yellow, flat, and hairy, with broad

36 BRITISH APHIDES.

tibise. They usually contain as many as six ova in
various conditions of maturity.

This Aphis appears to restrict its food to several
species of the lime or linden tree. It attacks Tilia
rubra, T. jplatyphylla , and T. grandifoUa, the leaves of
which shelter thousands on their under sides. They
eject the honey-dew in such quantity, that Kaltenbach
remarks that the traveller may trace the Aphis by the
viscid liquid which it sheds on the ground. In Swit-
zerland, the Aphides sometimes almost kill the trees ;
and at times so exhaust them of sap, that Boussingault
calculates that a single sick tree may produce as much
as three kilogrammes of sweet substance, which is
entirely the produce of Pterocallis tilicG,^ and elabo-
rated from the juice.

This Aphis, fortunately, is largely destroyed by
various parasitic Hymenoptera. As many as twenty-
four grubs may sometimes be counted infesting a
single Aphis, but at other times one large maggot
occupies almost the whole body- cavity, and apparently
without attacking the nervous centres, since the host
lives on and travels with its guest, as heavy as itself.
Such an example, on a smaller scale, I have figured in
Vol. II, Plate XLIII, fig. 6.

The puceron cle tilleul of Reaumur must be referred
to a different genus from the ordinary lime Aphis.
Eeaumur describes the insects as ranging themselves in
single file on one side of the leaf-stalk, and states that
by so doing they cause the stalks by their punctures
to curve into the form of corkscrews, the growth being
arrested on one side only. Reaumur also gives a figure
of this distortion. Kaltenbach points out that Linnaeus
and Fabricius, both quoted from Reaumur, and this
was copied into Miiller's translation of the ' Sy sterna
Nature.' Kaltenbach and others long failed to find
this "strongly convex" Aphis, which lives in com-
panies. Kaltenbach says it cannot be confounded with

* Vide Boussingault, " On Honey-dew j " vol. i, p. 42, of this Mono-
grapli.

PHTLLAPHIS FAGT. 37

the ordinary flat lime Aphis. He remarks, however,
that in 1842, " I had the luck to discover them on two
sheltered Hme-trees," and then he refers the reader to
Schizoneura Reaumuri of his work.

Kirby and Spence mention a gall on the lime-tree,
and also on the willow, both of which they say are the
produce of Aphides, but it is doubtful to what species
these have reference.

Genus XVIII.— PHYLLAPHIS,* Koch.

Rostrum very short.

Head convex, smooth.

Antennae moderately long, the third joint about
double the length of the fourth ; the fifth and sixth
joints equal, the sixth furnished with a representative
nail.

Cornicles hardly visible, and lying flat to the body.

Cauda almost obsolete.

Body furnished with long flocks of wool-like fibre of
a waxy nature.

Wings long and broad. Stigma long and trape-
zoidal. Nervures not clouded.

Legs moderate in size.

Phyllaphts fagi, Linn. Plate XCIV.

Aphis fagi, Linn., Fab., Walk.
Lachnus fagi, Burm., Kalt.
Phyllaphis fagi, Koch, Pass.

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-090x0'035 2-27x0-88

Length of antennae 0*060 1*52.

Cornicles wartlike „

* From ^i'XXoi', a leaf.

38 BRITISH APHIDES.

Body long, bright green or yellowish green, narrow
across the thorax. Abdomen, in the adults, spotted
with green in longitudinal rows, broadest on the
tergum. Cornicles mere tubercles, which scarcely rise
above the general surface. AntennsB greenish yellow,
and equally stout throughout; the last joint has a
process which Koch and some others regard as a true
joint. Eyes large and red.

The insect, during the summer, conceals itself from
observation by means of a quantity of white silky
material spun from pores spread on the thorax, and
more plentifully on the abdominal rings. This
cottony matter occurs in long flocks, which extend
beyond the tail, and make the insect apparently double
its real size. These insects crowd under the leaves of
the common beech, Fagiis sylvestris, and render them
hoary with this cottony mass.* Occasionally this accu-
mulates into resinous lumps, which have a sweetish
flavour on the tongue. Young specimens are but little
clothed, and, singularly, towards November the adults
spin less of this flocculent material.

Winged viviparous female.

Inch.

Millimetres.

Expanse of wings

0-300

7-62.

Size of body

0-110 X 0-040

2-79x1-01.

Length of antennae

0-060

1-62.

Cornicles wartlike

55

Head and thorax rather slender. Abdomen long
oval. Colour yellowish green. Head, prothorax, and
thoracic lobes black. Eight or more broad bands and
as many lateral spots mark the abdomen. Legs and
antennae black. The latter spring from inconspicuous
frontal tubercles. The sides and apex of the abdomen
are garnished with long flowing flocks as in the wing-
less female. Anal plates unmarked.

* As this substance is soluble in ether, it has more the character of
wax than either siik or cotton. Coccus, an allied family, as is well
known, produces both resin (lac) and wax (Cbiuese wax).

PTYCHODES. ' 39

Wings with the membranes rather bronzed. Cubitus
and veins brownish black. The former expands into
a fuscous and longish trapezoidal stigma.

This handsome fly is common in June wherever
varieties of the beech-tree abound.

The males.

Walker describes the winged male, which I have
not seen, but I have taken the apterous male in
company with the female late in October. It is
rather small and linear, its size 0*085 X 0'025 of an
inch ; bright green, rostrated, and furnished with
short and stout legs.

Apterous oviparous female.

Incli. Millimetres.

Size of body 0-070xO-030 l-77xO-76.

Length of antennae 0'030 0'76.

Colour of different shades, as bright green or reddish.
Some are destitute of all markings, but others have
brown spots ranged down the back and sides. The
flocculent substance is most plentiful on the lower
somites. They contain from six to eight eggs. They
appear from October to late in November, according
to the coldness or advanced character of the season.

Genus XIX.— PTYCHODES,* BucUon,

Rostrum very short and stout.

Head convex and broad, tufted with bristles.

Antennas stout ; first and second joints gibbous,
the third longer than the three following taken
together, the fourth and fifth nearly equal, the sixth
joint furnished with a nail-like process, as in
Phyllaphis.

* Fi'om Trruxw^'jG, striped or striated.

40 BRITISH APHIDES.

Abdomen fusiform, banded with colour.

Cauda small, pilose ; anal valves very marked.

Cornicles small, and buccinate in the winged
females.

Legs robust, short, and pilose.

Wings much shorter and narrower than in Galli-
pterus ; cuneato at the tips ; cubitus strong, nervures
dilated at their ends into triangular fuscous spots.

Ptychodes juglandis, Frisch. Plate XCV.

ApJiis juglaiidis, Frisch.
Lachnus juglandis, Kalt., Walk.
Gallipterus juglandis^ Koch, Pass.

It is remarkable that no description of the apterous
viviparous female of this species has yet been given
by any author. I have never met with it myself,
although not a few examples of the other forms have
come under my observation. This peculiarity recalls
the circumstance that the apterous viviparous female
of Drejjanosijjhum ijlatanoides is also unknown. Thus
these very different species would seem to show in
their metamorphosis a similar characteristic, which
amounts to this, that every insect which hatches from
the egg assumes wings before it commences its vivi-
parous multiplication. Unlike other species of Aphis,
every so-called larval form directly passes into a pupa
and thence into its imago.

Pupa.

Inch.

Millimetres.

Size of body

0-120x0'055

3-04X1-39.

Length of antennse

0-030

0-76.

cornicles

0-004

0-10.

Long oval. Head broad. General colour fine
yellow tinted with brown and greenish shades. Head
with an irregularly cleft rich brown mark, followed by

PTYOHODES JUGLANDIS. 41

four others on the prothorax. Abdomen furnished
with four longitudinal rows of squarish spots, so dis-
posed as to give much the appearance of transverse
bands. The very short cornicles are each seated on
one of the lateral posterior spots. Wing-cases very
pale, and edged with brown. Eyes red. Antennee
very short and tipped with brown. Rostrum hardly
longer than the head. Legs pale grey; hind pairs
very stout. The whole insect is pilose. The young
insects are born without wing-cases.

Winged viviparous female.

Inch.

Millimetres,

Expanse of wings

0-360

9-14.

Size of body

0'130xO-050

330 X 1-27.

Length of antenna3

0-060

1-52

,, cornicles

0-005

0-12

Large, bright yellow. Head, band on prothorax,
thoracic lobes, and nietathorax brown. Abdomen
yellow, with seven more or less interrupted transverse
brown bars flanked by two rows of marginal spots.
Cornicles very short, with their bases brown.
Antennse short and very slender, the seventh joint
being represented by an obtuse claw or nail. Legs
short, hairy, and stout.

Wings small and narrow for the size of the body.
Costal nerve and cubitus brown ; stigma paler ; other
veins brown, and expanded at their apices into brown
cloudy stains.

This handsome Aphis differs in several respects
from previously described allied forms. The short-
ness of the antennse and the aborted seventh antennal
joint, coupled with its very different shape, require its
exclusion from the last genus. Again, some signifi-
cance would attach to its modified metamorphoses,
and perhaps, too, from its habit of feeding exclusively
on the upper surfaces of the leaves of Juglans regia, a
habit not noticeable in Pterocallis juglandicola, the

42 BRITISH APHIDES.

other walnut species. Its bright colouring accords
well with its more exposed situation, and may act as a
protection from its enemies. From these considera-
tions I propose to place it in the above new genus ;
and this procedure will be in accordance with Mr.
Walker's views on the subject, as set forth in the
' Zoologist,' 2nd series, vol. v, p. 200.

Genus XX.-LACHNUS,* Illiger.

KlENLAUSE. BaUMLAUS. PiNE ApHIS.

nostrum slender, very long, always longer than half
of the body, and sometimes considerably longer ; last
joints hastate.

Antennae short, six-jointed, the last joint ends with
a nail-like process, which is the representative of the
seventh joint of other genera. The first two joints
are short and thick ; the third long, as long as the two
following taken together ; the fourth, fifth, and sixth
joints are equally long.

Cornicles small, not longer than broad.

Cauda none, or inconspicuous.

Legs very long, particularly the hinder pair ; the
tibi93 of which, in the oviparous females, are usually
dilated. Tarsi biarticulate.

Wings very long and broad, stigmata long and
narrow ; sometimes considerably encroaching on the
extension of the costa; stigmatic cells ovate. Cubital
veins twice forked. f

Lower wings with two oblique veins.

The genus Lachnus comprises some of the largest

* From Xd^vaiog, woolly, pilose.

t Kaltenbacli describes the antennEe as six-jointed, whilst Koch counts
in them but seven joints ; for he considers the nail as one. The former
author says that he has captured both Lachnus agilis and L. fasciatus
with their cubital veins but once forked. This tendency to the suppres-
sion of a wing-vein would seem to indicate a possible passage between
two genera ; or, viewed from the theory of development, it might show
that some individuals only have risen to the higher type.

LAOHNUS. 4S

species known in this family of insects. They are
noticeable on account of their varied habits and life-
history, and also for their ornate characters. Whilst
some kinds confine themselves to the soft rind of the
young branches of trees and shrubs, others find sus-
tenance within the crevices of the hard cortex of the
oak, the willow, or the pine-tree.

Most species are clothed with a dense fur-like coat
of thick hair, which circumstance suggested to Illiger
the name Lachnus, which implies such a character.
Often this protective covering is supplemented by the
peculiar flocculent matter seen so remarkably plentiful
in Phyllajjhis. Another characteristic of this genus
is the development of the legs, which are robust, and in
the hind pair attain to a great length. The hind tarsi are
distinctly biarticulate, the last joint with the claws being
much more developed than is seen in Aphis proper.

The rostrum is abnormally long. This development
is most remarkably seen in the rare species Stomaphis
quercuSj which exhibits the organ more than twice and
a half the total length of the body. Considered as a
proboscis, this insect has proportionally the longest of
all known animals.

The nectaries are in some kinds almost obsolete,
but others~possess them very small, and expanded as
to their mouths.

The tail is almost wanting, in accordance with Kal-
tenbach's remark, that this organ in its development
has a direct ratio to that of the cornicle. But although
these nectaries are so short, they do not preclude the
insect from the elaboration of honey-dew, for no
Aphides are more prolific in this secretion than the
LachnincB. On this account their presence on the
trunks and branches is often betrayed by the long file
of ants coursing up and down in quest of the liquid
with which they so much like to gorge themselves.*

* The sweet substance found in quantity on some plants in Italy, and
known as manna clei apicollori, is considered by Cannestrini and otbers
to be tlie product of certain Lachnina. Targioni-Tozzetti gives a
chemical analysis of this secretion in the * Bull. Ent. Ital.,' ix, p. 240.

VOL. III. 4

u

BRITISH APHIDES.

With the exception of the three oak species and the
single denizen of the willow, all the known British
Lachninse are feeders on Coniferse. Of these, some
affect the bole of the trees not far from the ground,
whilst others confine themselves very much to the
higher branches and are difficult to reach.

In order to balance the heavy bodies of these insects,
they possess broad expansive wings, which if not
adapted for swift flight, are still well suited for floating
in the air, and thus they are the means of transporting
the alate male to vast distances by help of the changing
winds.

Apterous males have been obscurely indicated by
Bonnet and De Geer. Koch also saw long narrow
green forms amongst the leaves of certain fir trees,
which he regarded as males.

Many of the larger kinds of Lachnus furnish an
intense red stain when crushed, but the elaboration
of this dye-like juice is not confined to the Lachninae.

Lachnus junipeei, Fahr. Plate XCVI, figs. 1, 2.

Ajyhis juniperi, Fabr., Schr., Walk.
Lachnus juniperi, Kalt., Koch, Pass.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0-110xO*070 2-79xl-77.

Length of antennae 0*060 1*52.

„ cornicles 0*007 0-17.

Very globose, sienna brown, very pilose, rather
shining, thoracic ring much corrugated. Abdomen
carinated. Head, thorax, and legs pitchy black.
Abdomen rich brown, with two large irregular spots
from which rise the obtuse and short nectaries. Head
broad. Eyes and antennae black. Under side rather

LACHNUS JUNIPERI. 45

more red, coxee black, a semilunar patch near the anal
plate. Rostrum black, and reaching to the third coxjb,
or beyond. Tarsi two-jointed. Storaata below, marked
by black dots. Some specimens show two tapering
bands which pass from the thorax down the upper part
of the abdomen.

Winged vivijparo^LS female.

Incli. Millimetres.

Expanse of wings 0*420 10*66.

Size of body O-lOOxO-050 2-54xl-27.

Length of antennge 0'050 1"27.

j>

cornicles 0*008 0*20.

Large, very hirsute. Head and thorax broad.
Abdomen globular, wrinkled. Cornicles conical, black,
and rising from black spots. Head, thorax, legs, and
antennas shining black. Abdomen rich reddish brown.
Wings ample. Membranes brownish ; insertions and
cubitus yellow. Stigmata brown ; veins very slender,
the second fork from the cubital vein encloses a very
narrow triangular cell. Two black spots on each anal
plate. Eyes, rostrum, and stomata black. Cauda
none.

Sometimes found in swarms on the common juniper,
Jimiperus communis, at Alnwick and Wooler in North-
umberland, and also on the bleak moors of the
Cheviott (Hardy). Kaltenbach apparently could only
find it on the same shrub (" Wachholder-Strauch,
Juniper-shrub,") in moist and warm places. Mr.
Hardy has found the black eggs on the twigs, and
sometimes plentifully.

De Geer states that the male is apterous.

46 BRITISH APHIDES.

Lachnus cupressi, BucMon. Plate Oil, figs. 1 — 3.

Apterous viviparous female.

Inch. Millimetres,

Size of body 0-080X0-055 2-02xl'39.

Length of antennee 0*050 1*27.

cornicles 0-005 0-12.

Colour ginger-brown or foxy-yellow. Head large.
Legs long and hairy. Eyes, nectaries, femoral and
tibial tips, and points of the antennse, dark shining
brown, approaching to black. Eostrum reaches beyond
the third coxse — about three fourths of the length of
the body.

Pupa.

Oval, domed, shining yellowish brown, hirsute.
Wing-cases honey -yellow. Both these forms are
smaller than the winged female.

Winged viviparous female.

Inch. Millimetres.

Expanse of wings 0*340 8*62.

Size of body O-154X0-035 3-91x0'88.

Length of antennae 0*040 I'Ol.

3J

cornicles 0*005 0-12.

Colour as with the above. Very hairy. Thoracic
lobes, cornicles, femoral and tibial points, brown.
Caudal end obtuse and setose. Wings moderately
long. Stigma long and dull brown. Other veins
black. Stigmatic veins straight and very stout. So
also are the second and third oblique veins. Hind legs
very long. Cornicles conical, and at their bases sur-
rounded by radiating bristles.

Live specimens of this ApLis were kindly forwarded
to me through Mr. McLachlan by the Hon. J. T.
Boscawen, of Lamorran, Probus, Cornwall. They

LACHNUS AGILIS. 47

were described as doing considerable injury to the
cypresses of the neighbourhood, towards the end of
the year 1879.

The insect has some resemblance in form to LacJmus
juniperi, but it certainly is quite distinct from it, and
the species has not been described before.

Note. — There has been an unavoidable error in the
order of the plates, occasioned by the fact that the
early plate was completed before the new Aphis was
described. Lachnus cupressi should come after Lach-
nus juniperi, and before Stomaphis qiiercus.

Lachnus agilis, Kalt. Plate XOVI, figs. 3 — 5.
Aphis agilis. Walk.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0*070 x 0-025 1770 X 0-620.

Length of antennae 0-035 0-880.

Cornicles wartlike.

Fusiform, pilose, green, speckled with numerous
minute reddish dots. Vertex and cauda tufted with
bristles. Head broad. Eyes brown. Antenna3 green.
Legs green and very long. Tarsi distinctly two-
jointed. Cornicles very small, almost invisible. Kos-
trum reaches to the first abdominal ring. Taken in
June when they contained many embryos.

Pupa.

Linear, bright green. Head, eyes, antennga, wing-
cases, and legs smoky black. Rostrum reaches to
the third coxae only. These insects are very nimble
in their movements, and to avoid observation run
quickly between the pinules of the Scotch fir,
Abies sylvestris, which tree they inhabit. They are

48 BEITISH APHIDES.

solitary in habit, being mostly found singly on tlie
green fir tufts. Towards the end of June or the
beginning of July they split their integuments and
disclose the imagos.

Winged viviparous female.

Incli. Millimetres.

Expanse of wings 0*200 5*08.

Size of body 0-070 X 0025 177 X 0-62.

Length of antennae 0'035 0'88.
Cornicles wartlike.

Green, slightly mealy. Antennae and eyes brown.
Thorax pale reddish brown. Legs long, yellowish
green, with dark femoral and tarsal tips. Wings rela-
tively small. Stigmata long, and stigmatic veins con-
tinued in straight lines beyond the same. The furcal
veins are often difiBcult to trace from their paleness of
colour and tenuity. The vertex is tufted with capitate
hairs ; the rostrum is rather short, and reaches only
to the third coxce. The apical rings are almost free from
bristles, and rather attenuated. I suspect that Koch
has in his figure 304 drawn an immature specimen of
Lachnus agilis for Laclmus pineti.

Taken at Haslemere and Bramshot, Surrey, in
June. Mr. Walker also forwarded me examples from
Walthamstow. The winged forms are difficult to meet
with.

Lachnus maorocephalus, BucMon. Plate XCYII, figs.

1 and 2.

Lachnus hyalinus, Koch (?).
Apterous viviparous female.

Inch. Millimetres.

Size of body 0-080x0-040 2-02x1-01.

„ antennaa O'OSO 076.

Cornicles wartlike.

LACHN0S MACROCEPHALUS. 49

Colour brown, ferruginous, or bright green; very
pilose. Head very broad ; vertex round. Eyes very
large, pale red or brown. Antennae rather more than
one third the whole length of the body, pilose. No
well-marked separation seen between the thoracic and
abdominal seofments. Abdomen with two double rows
of black or brown punctures disposed longitudinally ;
single dots occur on the thorax. Body covered with
a short woolly coat, particularly abundant towards
the tail end. Legs stout and clumsy. Femora strong.
Tarsi very long. Nectaries somewhat ferruginous.
Apical rings obtuse and pilose, with ferruginous hairs.
Eostrum short, only reaching to the third coxge.

Very similar in colour to the above ; bright green ;
head olive-brown. Eyes very large. Antennae and
legs furnished with ginger-coloured hair. Wing-cases
brown.

Winged male.

Inch. Millimetres.

Expanse of wings 0-280 7-10.

Size of body 0-080 X 0-023 2-02 X 0-57.

Length of antennse 0*035 0-88.

Rostrum 0-050 1-27.

Body linear. Head very broad ; front convex and
hairy. Antennae remote at their insertions ; the third
joint equal to the four following joints taken together.
Eyes bright red and large. Ocelli obvious. Head, pro-
messo- and post-thorax rich brown. Thoracic lobes
small. Abdomen shining green, long, and carinated,
furnished with small tubercles, which are tufted. Whole
insect sparsely covered with meal-like matter and
short cotton-like filaments. Wings ample, with
brownish iridescent membranes. Costa and stigma
brown. Nervures very slender, brown ; the second
and third oblique veins much thicker than the others.

50 BEITISH APHIDES.

Rostrum very long, last joint hastate. Legs brown,
and like the rest of the body, covered with ginger-
brown hair. Tarsi long.

Several apterous specimens were sent to me from
the spruce firs at Walthamstow late in June, and in
July also I found this insect numerous at Branisliot on
the same conifer, Ahies excelsa. The winged males I
bred in confinement ; they emerged from their pupee
on July 26th. Like most of the Lachninge they were
very nimble and by no means easy to secure whilst
hiding amidst the pinnules of the fir sprigs.

The apterous insect fairly agrees with the descrip-
tion given by Koch of his L. hyalinus ; and his figure
also fairly agrees with my insect. On the other hand,
the winged form of L. hyalinus is described as rusty
red, and as being very indistinct as to the third oblique
veins on the upper wings. Koch's figure of the winged
female differs very much from mine. I prefer, there-
fore, to mark L. hyalinus as a doubtful synonym.

This insect may be separated from Lachnus agilis
by its less linear outline, its darker colour, its larger
head, its greater hairyness, larger stigma, and more
pronounced wing-veining.

I cannot say whether each species confines itself to
one particular species of pine.

Lachnus pini, Linn., Plate XCYII, figs. 3, 4.

Aphis pini, Linn., Walk.
Lachnus pini, Kalt.
Aphis nuda pini, De Geer.
Pityaphis, Amyot.

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-140 X 0-075 3-55 X 1'89.

Length of antennae 0*065 1*64.

„ cornicles 0*005 0*12.

LACHNUS PINI. 51

Very large. Colour of various shades of brown, but
usually of a dull brownish, grey. Strongly pilose, par-
ticularly on the abdomen, which is soft and velvet like.
Whole body finely punctured with dark brown dots.
Dark patches occur on the front, the thorax, and the
apical abdominal rings. Head large ; eyes black and
prominent. Antennae fine, the third and fourth joints
cinereous brown, the other joints black. Legs very
stout and long, the hind pair particularly so. Colour
pale drab with black femoral and tibial tips. Tarsi
double-jointed and long. Cornicles obtuse and conical.
Rostrum stout and about three quarters the length
of the whole body. The whole insect is clothed with
tawny hair.

Active in its habits, like the last two species, it
rapidly threads the green pinnules of the Scotch fir,
Pinus sylvestris, to avoid observation. It is solitary
in its haunts, occurring sparsely on the older twigs,
with the bark of which it assimilates so well in colour
that it easily may be overlooked, except from the small
tufts of cotton-like fibre that it attaches to the leaves.

Taken at Haslemere and at Southgate in June ; but
it appears to be rather restricted in locality.

Wijiged viviparous female.

This form is fully described by Kaltenbach and by
Walker. It is reddish brown and covered with yel-
lowish hair. The thoracic region is studded with
black punctures.

De Geer makes some lengthy remarks on this Aphis
under the name of Aphis nuda pini. The colour of
the wingless forms is dependent on age. They occur
occasionally of hues — yellowish, greenish, and reddish
brown. Living specimens of these I have not met
with.

62 T5EITISH APHIDES.

Lachnus pinicolus, Kalt., Plate XOYIII.

Lachnus finicola, Kalt., Ratz., Pass. y
Aphis pmicola, Walk. ^

Apterous viviparous female.

Incli. Millimetres.

Size of body 0'150X-090 3-81 X 2-27.

Length of antenna 0-070 1-77.

Cornicles very small.

Large, oval, narrow towards the head, which last is
rather broad. Antennae stout. General colour of the
body chocolate brown, with patches of grey glaucous
bloom. Numerous large and small spots occur down
the dorsum and the sides. First three antennal joints,
the upper half of the rostrum, and all the legs, fine
ochreous yellow. The tips of the rostrum, the an-
tennae, the lower halves of the femora and the tarsi,
dark rich brown. Rostrum long and stout ; it extends
beyond the third coxEe or even longer. Eyes brown,
as also are the very short cornicles.

The pupas have orange-coloured bodies, with two
rows of brown dorsal spots, and dark brown wing-cases.

Winged viviparous female.

Incli. Millimetres.

Expanse of wings 0*400 10*16.

Size of body 0*100xO-035 2-54x0*88.

Length of antennae 0*060 1*52.

Smaller than the apterous female and not so robust.
Head large and broad. Colour orange-brown. Tho-
racic lobes black. Abdomen brightly coloured, with
a broad, undulating, brown dorsal stripe, ornamented
with numerous white trapezoidal spaces. Two lateral
brown stripes occur down the sides. Legs long, par-
ticularly the hinder pair. Antennae and legs fine yel-
low, the last with black femoral and tibial tips.

LACHNUS VIMINALIS. 53

Abdomen finely pilose. Wings very long ; insertions
yellow ; cubitus brown, ending in a long and narrow
brown stigma. Apical cell long oval.

Twenty-nine of these fine insects were bred from
pupse early in October, all of which formed the pro-
duce of one large apterous female. The young are, as
usual, born tail foremost, and are enveloped in a fine
membrane which, while the head of the young is still
attached to the parent, is slowly worked ofi" to the tail
k in wrinkles, and then cast off. The young are exceed-
P ingly active ; and even when adult, the insects, pupa3
and all, run to the opposite sides of the branch of fir
twigs on which they feed, to avoid observation.

This Aphis forms small clusters at the bases of the
green tufts of the larch, Pinus larix, but usually it

^ occurs in greater profusion on the Scotch fir, Pinus
sylvestris, the bark of which assimilates very closely to
the general colour of the insect, and thus conceals it.

The queen Aphis, or foundress, will live for a con-
siderable time ; and will scarcely, unless alarmed, move
^ from her place of feeding. I have marked a single
specimen which was so located for three months.
Her young ones, which possessed long rostra, mi-
grated, but she remained fixed.

Lachnus pinicoJus is a prey to an Aphidius. Many
examples may be found perforated by this parasite,
with the curious flaps cut out of the skin of the
Aphis erect, and attached by a sort of hinge to the
hole. These Aphides are much sought after by ants.

Lachnus pinicolus appears to be rare near Parma.
Koch does not notice it in his Monograph. The tarsi
are distinctly ^w;o-jointed, and this appears most
markedly in the hind legs of the winged insect.

Lachnips VIMINALIS, Fonsc, Plate XCIX.

Aphis viminaUs, Boyer de Fonscolombe.
„ salicis, Shaw (?).

54 BEITISH APHIDES.

Aphis salicis, W. Curtis (?).

,, saligna, Walker.
Lachnus viminalis, Pass.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0-160X0-12O 4-06x305.

Length of antennse 0-070 1-77.

„ cornicles O'OIO 0-25.

Very large, globose, shining from a fine pile of silky
grey hair. Colour dark ochreous brown. Head
small, front flat. Antennae short and slender, reddish
at their bases but black at their tips. Two cm^ved
spots on the thorax. Abdomen very globose ; centre
of the dorsum furnished with a characteristic horn-like
eminence. Cornicles large and obtuse. The dorsum
has several rows of large transverse black spots.
Cauda none. Legs long, particularly the hinder pair ;
pilose.

Pupa.

More elongated than the larva ; colour very similar.
Wing-cases sienna-brown, as also are the upper parts
of the tibiae. Dorsal tubercle large.

Winged viviparous female.

Incli. Millimeti'es.

Expanse of wings 0*600 15"24.

Size of body 0-180x0-070 4-56xl'77.

Length of antennae 0*070 1-77.

„ cornicles O'OIO 0'25.

Very large, general colour like the above insect.
Head small. Antennae very short and slender.
Thorax robust. Abdomen oval, spotted with black,
the largest spot being placed in the middle ring.
This spot, which is covered by fine silky hair, seems
to be the representative of the large tubercle pos-

LACHNUS VIMINALIS. 55

sessed by the apterous female. Cornicles olotuse and
very obvious. Rostrum reaches scarcely beyond the
third coxse. Wings very long, and mostly carried
horizontally when at rest, instead of pent-wise.
Membrane rather coarse and hardly iridescent ; inser-
tions and cubitus orange-yellow ; stigma very long,
narrow, and brownish black. Veins fine and pale
brown; first and second furcal nervures, soon after their
origin, run nearly parallel. Costal nerve of the under
wing nearly straight. Hind legs very long; all the
tibife ochreous red ; tarsi distinctly biarticulate.

This Aphis, when' crushed, yields a deep port-wine
red stain, which is intensified by the action of an alkali.

I have no doubt that this insect is AioMs saligna of
Walker, although he omits to notice the characteristic
dorsal tubercle, or rather he calls it a large black spot,
between the nectaries. Passerini remarks that Walker
has erroneously written Aphis saligna, Sulz., for A.
salicis, Sulz., and that the last Aphis is a species
" omuino aliena."

Shaw, many years ago, in his ' General Zoology,'
mentions, amongst others. Aphis salicis, and refers to
Curtis' s paper on Aphis in the sixth volume of the
'Linnsean Trans.,' where the insect is described as
" nearly a quarter of an inch large, and one of the
largest species," feeding on willow bark and not on the
leaves. " Towards the end of September," he says,
" multitudes of the full-grown insects, winged and
otherwise, desert the willows on which they feed, and
ramble over every neighbouring object in such a
manner, that we can handle nothing in their vicinity
without crushing some of them. Younger individuals
still remain in large masses on the trees." He says
they are yellowish grey, spotted with black, and that
they stain the fingers red.

Sugar must have been difiicult to procure in his day,
we may suppose; for William Curtis says, "their secre-
tion might be gathered and, by purification, converted
into the choicest sugar or sugar-candy." Though

56 BRITISH APHIDES.

wasps feed greedily upon it, bees appear totally to
disregard it.

The late Mr. Alfred Smee told me that an Aphis,
which proved to be this Lachnus^ swarmed in such
thousands on his willows at Carshalton, that trees
thirty or forty feet high had been killed by their
poisonous influence.

I have received in June specimens from Carshalton
and, through the kindness of Mr. Evershed, also from
Shere, near Guildford. My friend Mr. James Salter
found a cluster of them on one of his willow trees,
near Basingstoke, five inches long, and an inch wide.
The insects were ranged very closely together, side by
side, with all their heads turned downwards, and on
tlie lee side of the branch. The members of a swarm
usually remain for a long time motionless, but if a
single one is by any means disturbed it throws up its
hinder legs with a jerk, in a tentative manner, and this
movement is speedily communicated to all the indivi-
duals of the general mass. The action may be
deterrent, to prevent parasitic attacks of Hymenoptera.
I have attempted to represent this action in fig. 5, on
Plate XCIX.

Several species of Aphides carry their wings hori-
zontally when at rest, like the common house-fly, and
some authors have considered this of generic import-
ance. Although doubtless the position is exceptional
amongst Aphides, too much value must not be placed
upon the circumstance, for it may be seen in several
Pemjphignicey and also in Thelaxes {Vacuna, Heyd.).
In Lachniis viminalis these two positions are indiscrimi-
nately adopted. The use of the conical tubercle on
the dorsum is not certainly known. Although the
apex is furnished with several minute pores, the
organ may be regarded as blind or imperforate. It
has not the function of a nectary, but probably that
of an odoriferous gland.

It would appear that this Aphis has considerable
facility of migration from spot to spot, and that this

LACHNUS VIMINALIS. 67

journeying is practised by the wingless individuals en
masse. Mr. James Salter observed that a large patch
of these insects had collected on the bark of a willow,
Salix daphnoides ; they appeared to screen them-
selves from the rough and rainy south-west wind then
blowing by retiring to the north-east side of the stem.
Four days later the same tree was visited by him, but
not a specimen could then be found by a most careful
search. On turning to another willow, Salix acumi-
nata, about five feet from the former tree, which
certainly was not infested four days before, the missing
patch was found. It is possible that this movement
was caused through their previous disturbance and
observation. If so, their march must have been very
persevering and determined, for the intervening
ground was covered by rank grass and weeds, ten or
twelve inches high. Cold November weather set in a
week later, and then not a single Aphis could be found
in places where previously, in another part of the
salictum, " myriads might have been collected without
difficulty."

In Nottinghamshire this Aphis is sometimes very
common. Its visits are intermittent, but I learn
through a resident horticulturist that the harm they
do to the trees is not at all marked. Mr. Smee's
experience, however, would seem to be otherwise.

Mr. Salter sent me in the following March some
thick willow stakes that had been infested durino- the
previous year. The effects of their puncturing was
conspicuous as brown stains disposed in stripes on the
grey bark. I could, however, discover no trace of
egg or hibernating female in the crevices, though
assisted by a lens. Whether the insect descends to
the earth for its winter shelter or not, is a question for
a future observer to settle.

I believe that the Lachnus dentatus of Le Baron,
of America, is identical with Lachnus vimmalis, see
* Third Annual Report of Noxious Insects in Illinois,'
by Dr. Cyrus Thomas, 1879, p. 116.

^8 BRITISH APHIDES.

Laohnus PICE.E, Walk. Plate C.

Lachnus grossus, Kalt.
Aphis jpicecB, Panz.

Apterous- viviparous female.

Inch. Millimetres.

Size of body 0-190 X 0-090 4-81 X 2*27.

Length of aiitenn93 0-070 1-77.

Cornicles wartlike.

Yery large, long oval. Head and thorax shining
pitch black ; the latter pitted with depressions. Eyes
prominent, black. Antennas very short and attenu-
ated, black, the two last joints tuberculate. Abdo-
men smooth, domed, slightly carinated, colour dull
sooty black, lustreless. The ring, fourth from the
apex, covered with a cinereous mealy coat, v^diich is
continued to the under side. Cornicles very small.
Cauda none, but the anal ring is garnished with
brown hair. Legs pilose and very long, particularly
the hind pair ; colour rich sienna-brown, with black
femoral and tibial points. Tarsi distinctly two-jointed.
Postrum very long, but it does not extend beyond
the caudal end, black.

This is a large and handsome species. Numerous
specimens were kindly sent to me in the month of
October by Mr. Joseph Anderson, of Alresford, Hamp-
shire, where he found them in the greatest profusion
on the trunks and boughs of the spruce fir, Abies
excelsa. A severe frost set in the evening after these
insects were captured, and the next morning all bad
" vanished as if by magic." A few days afterwards
sunny weather again set in, and the insects once more
came out in full force. The sudden disappearance
and the reappearance of this and other species is

LAOHNUS LONGIPES. 59

remarkable, and difficult of explanation, for on one
day trees may be black with tliem, and the next day
none can be found, even by a careful search of the
earth at the base of the trunks before infested.

The attacks of this species are often confined to
particular trees, and in particular plots ; sometimes a
single spruce in the midst of others is alone infested.

Mr. Fitch, of Maldon, failed to obtain for me a
single winged female ; and I was unable to breed any
from numerous apterous specimens he kindly for-
warded, notwithstanding that I for some days kept
them in confinement.

On the 28th of December of the same year, and
from the same entomologist, I obtained some small fir-
tufts of spruce which were covered with the black
shining eggs of this same species. These ova were
glued to the green pinnies in rows, a drawing of which
may be seen in Plate C.

Walker met this species in great abundance on the
silver fir, Abies picea; and near London on the spruce.
He took it also frequently on the firs of the Grimsel
Alp, and it has been likewise found in Siberia. The
winged insect has very large wings, and has a colouring
very similar to the larval form above noted.

Kaltenbach describes Ajohis picece of Panz., but he
thinks that probably it is identical with Lachnus
innicolus.

I have failed in precipitating the red dye formed
by this and other Lachnince, as a lake or a carmine
compound : thus it does not imitate the behaviour of
solutions of cochineal or madder.

Lachnus longipes, Ditfour. Plate CI, fig. 1.

Ajyhis longipes,iLmn} Dufour.

,, rohoris, Fonsc.
PterocJilorus longipes, Rond. and Pass.

VOL. III. 5

60 BRITISH APHIDES.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0-170xO-070 4-31xl-77.

„ antennae 0*080 2-02.

Cornicles wartlike.

Long oval, uniformly deep brown. Antennae very
slender. Eyes black. Cornicles conical and small.
Rostrum about equal the body. Apex hastate.
Femora stout. Tibiae curved. Cauda none. Ab-
dominal apex setose.

The young are Hnear, with disproportionately long
rostra and hind legs.

Winged viviparous female.

, Incli. Millimetres.

Expanse of wings 0720 18*20.

Size of body 0'180xO-079 4*56xl-99.

Leno-th of antennae 0*080 2*02.

cornicles 0*005 0-12.

This is one of the largest species comprised in the
genus ; the winged form in expanse attaining to three
quarters of an inch. Its general colour is of a rich
brownish black. Abdomen large, oval, and glabrous.
Antennae short and slender, the third joint much
tuberculate and as long as the fourth and following
joints taken together. Eyes black. Cornicles conical,
with large bases. Cauda none. Legs long, particu-
larly the hind pair, very hairy, bright orange with
black femoral and tibial joints. Tarsi double-jointed
and black. Rostrum moderate, reaching to the third
coxse only. Wings very long and broad in the middle.
Cubitus with broad yellow insertions, which end in
long narrow stigmata ; these last attain to one third the
length of the wing. The anterior costal nervures of
both upper and under wings black, but all the other
nervures are orange-yellow. Stigmatic vein nearly
straight.

STOMAPHIS. 61

Taken plentifully late in December by F. Fitch, Esq.,
on exposed oak stumps at Maldon, Essex. Though 30
numerous, no apterous forms could then be found,
probably they were preparing to give birth to the
perfect sexes, which would furnish the eggs for the
next year's progeny.

This insect is not very unlike the winged form of
Lachnus picece, but it is much larger. The food of the
two insects is different. It has considerable resem-
blance to the fine American species described by Prof.
T. Monell,of the Missouri Botanical Gardens, St. Louis,
and which he names Lachnus longistigma. This last
insect has, however, the stigma continued round the
greater part of the stigmatic cell, as a brown border,
which certainly is not seen in the British insect.

Passerini in his diagnosis of Pterochlorus longipeSi
says, " Alge stigmate trapezoideo," which hardly agrees
with the insects I have seen. He also says that L.
longipes affects the sweet chestnut Castanea vesca, as
well as Quercus rohur and other kinds of oak. He
gives a caution that it is not to be confounded with
Aphis roboris of Linngeus, which does not occur in
Italy.

Dufour's description answers well to the above
diagnosis, except as to the words " Alis maculis duabus
magnis atris subfenestratis," which might possibly
apply to the stigmata. .

Genus XXI.— STOMAPHIS,* Walhr.

Head and eyes small. Antennae slender, moderately
long, six- jointed, third joint the longest, the sixth as
long as or longer than either the fourth or fifth, the
aborted seventh joint longer than in Lachnus. Cor-
nicles very inconspicuous. Legs shorter than in
Lachnus^ and less stout. Tarsus biarticulate. Tail

* From a-Tofia, a mouth, and afig.

62 BRITISH APHIDES.

none. Rostrum very long in the apterous females,
but shorter in the wiugecl forms. According to
Walker altogether wanting in the males.* The four
joints sometimes equal three times the whole length
of the body. Setae very long and convoluted.

Wings very short, a little longer than the body
(Walker), and carried horizontally (Reaumurf). Stig-
mata rhomboidal. Stigmatic vein curved (Kalt.).

Stomaphis queeous, Reaum. Plate 01, figs. 2-

Puceron de Ghene, Reaum., Bonnet.
Aphis quercus, Linn., Walk.
„ longirostris, Fabr. (?).
Lachnus quercus, Kalt., Walk., Pass.

Apterous viviparous female.

Size of body
Length of antennae
„ rostrum

Very large, shining brown, rather hairy, oblong.
Head small. Byes brown. Legs moderately long and
fine. Antennee slender ; about half the length of the
body ; brown, except the third joint, which, like the
femoral and upper tibial portions, is ochreous yellow.
Rostrum very long and trailed between the legs whilst
walking, so that this protruding organ appears like a
long tail. Cauda wanting.

Found, from July to October, on the stems of the
oak, into the bark of which the insects thrust their
rostra so deeply that they can be removed with diffi-
culty. The antennae are usually rapidly vibrated,
somewhat in the manner seen in the Ichneumonidce,

* Mr. Walker tliouglit that there were sufficient structural diflfer-
ences in this Apliis to separate it from Lachnus. Although he did not
publish any generic characters, he suggested the above name, which I
have gladly adopted. Vide ' Cat. Horn. Insects,' part iv, p. 961.

f Reaumur, 'Mem. des Insect.,' iii, 334, pi, xxviii.

Inch,

Millimetres.

0-210 X 0-080

5-33.

0-100

2-54.

0-570

14-44.

STOMAPHLS QUERCUS. 63

and this action is continued during the visits of the
black ant, Formica fuliginosa, which by trooping np
and down the branches of the trees often betrays the
presence of the Aphis. The winged form appears to
be exceedingly rare. Neither "Walker, Passerini, nor
myself have ever met with a living specimen. Kal-
tenbach, however, describes it, and he notices that
there are winged and apterous males, both of which
are of diminutive size.

This Aphis is very scarce in England, but at one
time it seems to have been somewhat common in
France and Germany. It has been described with
some particularity by Reaumur * and Bonnet, and
afterwards by Kaltenbach. It is not, however, in-
cluded in Koch's list of Lachnince.

Mr. Walker communicated to me the following note
on this insect in answer to my inquiries :

" I think Tugall was the first person to discover
Aphis quercus in England, and he mentioned it to
Stephens, who published a notice thereon about 1847 ;
but I do not find it mentioned in the list of writings
of the latter author. About that time Tugall directed
me to an oak near Dulwich, where I fonnd it ; and
some years after, the late Mr. Alfred Smee told me of
an oak at Weybridge, where I found it again, and
subsequently I met with it at Finchley. I have only
named, not described it, as Stomaphis, though I think
that it is sufficiently peculiar to be separated from
Lachnus. The male is mouthless, or rather it has no
rostrum."

Bonnet describes an Aphis which I think must be
referred to the above insect. He says it is remark-
able for the magnitude of its trunk. " Le puceron de
chene — c'est I'elephant des pucerons," and as large
as an ordinary fly. It attaches itself to the branches of
the oak, which "on commence anoircir." La couleur
" brun fence terne sur le dos, pen luisant sous le
ventre;" legs, antennse, and trunk, "rouge maron."
* ' Mem. des Insectes,' ix, p. 334, torn, iii, 1734.

64 BEITISH APHIDES.

Lengtli of the trunk about twice that of the body.
They occur winged and apterous, but the former are
less common. " The wings are carried perpendicu-
larly, like those of a butterfly." The insects have an
" odeur assez forte." Other authors do not seem
to have noticed this character. Bonnet thinks this
long trunk is used for probing the crevices of the bark
as well as for suction.

He also discovered the apterous male ; he gives a
ludicrous account of the insect's antics during court-
ship, and he states that both antenn83 and legs are
rapidly vibrated at the same time.

Passerini remarks that Lachnus longirostris is diverse
from Lachnus quercus. The food certainly is different,
for the former insect feeds on the willow and the
poplar, instead of on the oak.

Linnaeus probably describes this insect under the
name of Aphis quercus. He gives for characters, " Pro-
boscide longissima, habitat in corticibus quercus in
Grallia. Maxima nostratum atra, alse hyalinse margine
externis atro, antennarum pedum que articuli basi
ferruginei. Rostrum longitudine abdominis. Ab-
domen muticum.

Genus XXII.— PARACLETUS,* Heyden.

Rostrum variable in length, but shorter than in
Trama.

Antennge six-jointed, with a nail at the extremity of
the sixth ; third, fourth, and fifth joints nearly equal.

Cornicles : none.

Legs long ; tarsi biarticulate ; claws two.

Eyes moderately developed. In this particular it
differs from Trama.

* From TrapaK\r]Toe, a consoler ; probably referring to these insects
l^eing cherislied guests in the nests of ants.

PARACLETUS, 65

Winged forms unknown.*

Reaumur, more than one hundred years ago, found
Aphides in ants' nests ; but Von Heyden was the first
to assign genera for these insects. Paraoletus, Forda,
and Trama comprise some minute species which, so far
as observation yet goes, are apterous and subterranean
in habit. Burmeister subsequently added BMzobius,
which expresses an underground habit ; and Passerini
has found it convenient to class these several genera
together under the section Bhizohiince, an arrangement
which for the present may be considered good. Some
name must be found for tribes or sections, and it is
difl&cult to avoid meanings too distinctive in such
names — distinctions which further research might
render it necessary to qualify.

Root-feeding Aphides are now known to obtain in
many dissimilar genera, such as Siphonopliora, Aphis,
Schizoneura, Pemphigus, and Phylloxera. It would,
therefore, seem to be desirable that all comprehensive
tribes should have some trivial name which shall not
be too exclusive on the one hand, or unmeaning on
the other.

It has long been a problem to solve what habit and
condition are assumed by those Aphides which appear
to be restricted to short-lived annual plants for their
sustenance. When such plants die and become rotten,
what becomes of the insects during the eight months
when no food seems fitted for their use ? Three
hypotheses may be advanced to meet this difficulty.

1st. Immediate descent into the soil, attended by
subterranean oviposition.

2nd. Migration of the imperfect females to plants of
other species, followed by complete development of the
cycle upon that plant.

3rd. Dimorphism, amounting, perhaps, in some cases,
to the passage into more complex forms, hitherto regar-
ded as stable species in the ordinary sense of the term.

* Walker's description, if sucli, appears to me too vague to allow of
identification. Vide ' Cat. Homop.,' vol. iv, p. 1062.

66 BRITISH APHIDES.

Hypothesis No. 1 has the great disadvantage that
the young brood when hatched must be generally too
far removed from their natural food to make it pro-
bable that they would ever meet it. The ova also
would remain many months under ground during the
autumn, perhaps without development.

No 2. — Migration to other plants certainly takes
place in several instances. Walker asserts it, with con-
siderable probability of the hop Aphis^ whilst the om-
nivorous character of the bean and the plum Aphis,
and also that of the wheat is very clear. Lichtenstein
states the same habit is assumed by Dy^yobius and
Scliizoneura.

No. 3. — Dimorphism, with great change of economy,
has been conclusively proved in the vine pest, Phylloxera
vastatrix ; and there seems little reason for doubt that
persevering workers will prove a similar habit in other
genera.

Thus, we may expect that some root-feeding
Aphides will be proved to be dimorphs of some well-
known aerial species; and conversely, that others
hitherto supposed to be strictly aerial, whose existence
has now been traced only to two or three months'
duration, wnll eventually be referred to subterranean
feeders with other specific names.

These remarks are made as introductory to two
genera which are in a sense exceptional ; inasmuch as
some characters would ally them to the Lachnince, and
others to the Jphidince. Koch places Trama low in
the scale, even after Pemphigus. Passerini places
Trama and Paracletus amongst the Apliidince. If
these species should ever prove to assume wings, I
think it probable they will show the venation of
Laclmus. The character of their antennoa and laro-e
development of their rostra better also accord with
Laclmus than with Pemphigus, and therefore I here
place them in sequence.

PAEACLETUS CIMIOIFOKMIS. 67

Paracletus cimicifoemis, Heijd., Plate CII, fig. 4.

Kali., Pass.

Ajpterous viviparous female.

Inch.

Millimetres.

Size of body

0-080 X 0-040

2-02X1-01.

Leugth of antennee

0'040

1-01.

.Oval, flat, somewhat shining ; colour wax-yellow,
naked. Head rounded, with a furcate mark on the
vertex. Eyes small, but obvious. Antennae six-
jointed, hairy, yellowish, and about half the length of
the body. Abdomen carinated and garnished with
rows of small dots.

This Aphis does not appear to be plentiful anywhere.
It has mostly been taken in the nests of Formica rufa,
and then usually in company with another underground
Aphis , For da fo rmica ria .

It has somewhat the appearance of the bed-bug,
whence its name, but it is active in its movements, and
runs quickly. Kaltenbach found about fifty of them, in
the month of April, in one nest, where he considered
that they had passed the winter in friendly relations
with the ants.

Passerini found them on the roots of Festuca durius-
cula. Like Kaltenbach, he notices that the wing-ed
form IS unknown ; but Walker describes the veining of
the wing of an example that he appears to have met
with. Unfortunately, he does not even say if the cubital
vein is twice or only once forked. His description,
indeed, leaves it doubtful whether his insect was a
Schizo7ieura, a Lachnus, or other genus.*

* Walker's ' Cat. Homop. in the British Museum,' vol. iv, p. 1062.

68 BRITISH APHIDES.

Genus XXIII.— TRAMA,* Heyden.

WUEZELLAUS. ROOT-APHIS.

Rostrum large, at least two thirds of the length of
the body. Much longer in the young.

Antennae about half the length of the body, six-
jointed, excluding the apical unciform process; third
joint the longest, and about equal to the fourth and
fifth taken together. Fifth and sixth joints equal.

Cornicles none, or mere pores.

Legs long, particularly the hind pair, which possesses
only one long tarsal joint, which equals the femur in
length. The other tarsi two-jointed. Claws two.

Tail inconspicuous.

Eyes very small ; almost obsolete.

The winged form has never been described, and its
existence was unknown to Heyden, Kaltenbach, and
Passerini. On the other hand, Walker says that the
insect " occasionally, but very rarely, acquires wings,"
but he gives no authority for the fact.f

Kaltenbach describes Trama in one place as having
seven antenna! joints, but in another only six. The
process at the end of the sixth joint appears to me to
have no greater claim to be regarded as an articu-
lation than that seen in Lachnus, which is quite as
much developed.

Teama troglodytes, Heyden. Plate CII, figs. 5—7.

Walk., Pass.

Trama radicis, Kalt., Koch.

,, lyuhescens, Koch.

,, flavescens, Koch.
Aphis radicum, Goureau.
Ehizobius heUanthemi, Westw.

* Derivation doubtful,
t Walker, op. cit., p. 1061.

TEAMA TROGLODYTES. 69

Apterous viviparous female.

Inch. Millimetres.

Size of body 0'115x 0-060 2-92xl'52.

Length of antennas 0*065 1'64.

Body long oval, slightly domed, ringed and cari-
nated, hairy. Colour greenish or yellowish white,
transparent. Head rather small; eyes almost rudi-
mentary. Antennae about half the length of the body,
six- jointed, the last being provided with a nail.
E/Ostrum long, but the length varies with age. In
young examples it projects beyond the abdominal
apex. Legs long, particularly the hind pair, which
have largely developed tarsi, furnished with a double
claw. By these tarsi the insect may be readily sepa-
rated from all other described root-feeders. The long
hind legs are often vibrated, and occasionally they are
jerked upwards in the manner affected by several
LaclinincB.

When the insects are unearthed they appear of a
pale semitransparent hue, but by exposure to the air
the antennge and legs speedily become browner.

Trama troglodytes feeds on a variety of roots.
Amongst these may be named Leontodon taraxacum,
Cnicus arvensis^ Sonchus oleraceus, Lactiica saliva,
Hieracium pilosellaj Crepis biennis, and Artemisia
vulgaris.

Heyden found small companies of this species
domiciled in ants' nests ; and Sir John Lubbock, from
Beckenham, and Mr. Hardy, from the Grampian Hills,
have obligingly forwarded examples to me taken from
similar localities.

The part played by these Aphides in the economy
of these ants is not very obvious. Their presence can
scarcely be for affording food to their hosts, for the
absence of nectaries seems to preclude the secretion of
the nutritive honey-dew. Such an explanation, more-
over, will not account for the like presence of various

70 BRITISH APHIDES.

remarkable blind beetles, onisci, and centipedes, wliich
are also the known denizens of ants' nests.

These apterous Aphides may be taken in such
situations till late in November, and probably there
they hybernate. Aphis radiciiin, Goureau, is referred
to Trama by Boisduval. Trama troglodytes is frequent
on the high moors in Berwickshire, and mostly located
in the nests of Myrmica nihra or Formica fuliginosa.

Genus XXIY.— DRYOBIUS,* Koch.
Knopperlause. Clouded Oak- Aphis.

Rostrum rather long and thick, projecting beyond
the post-sternum. Much longer in the young.

Antennae slender, six-jointed, with an unciform
process on the sixth joint. Third joint more than
twice the length of any other. The fourth and fifth
joints about equal. The sixth less than half the
length of the fifth.

Cornicles conical, and very short.

Cauda inconspicuous and rounded.

Legs, the first two pair moderately long, the hinder
pair disproportionately long ; tarsus composed of two
distinct joints.

Wings moderately long in the males, but very short
in the viviparous females. Stigmata rather long.
Cubital and first furcal veins issue from the same
point, which is at some distance from the cubitus.
The membrane of the upper wings variegated with
brown smoky fasciae.

* From Spvc, an oak, and /3iow, to live. Prof. Monell warns me that
there is an American lepidopterons insect named Dryohius sexfasciatus.
I have failed to learn anything definite about this insect, or whether
Dryobius can claim priority as a lepidopterons form over that genus as
an Aphis. Koch's commenced to publish in 1854. Mr. McLachlan
informs me that Dryobus is a coleopterous genus which approximates
to the above name. In this uncertainty I retain Koch's nomenclature.

DRYOBIUS ROBOEIS. 71

N.B. — It may be noted that in some Aphides the
rostrum attains its full development and length at the
early stages of life. There seems afterwards to be an
arrest of growth. In some genera to follow, this organ
in the young projects far beyond the end of their bodies,
whilst in the mature forms the proboscis hardly attains
to the third coxa.

Detobius eoboeis, Linn. Plate CIII.

Aphis roboris, Linn., Fonsc.
Lachnus fasciatus, Burm (?).
Cmara rohoris, Curtis, Sir 0. Mosley.
Lachius Qvhoris, Kalt.
DryapMs, Amyot^.
Dryobius roboris^ Koch.

Apterous oviparous female.

Indies. Millimetres.

Size of body 0-150 X 0*090 3-81 x 2'27.

Length of antennge 0-070 1-77.

cornicles 0-010 0-25.

S9

5>

rostrum 0*060 1*52.

Oval, anterior portion produced. Head and thoracic
segments narrow. Abdomen broad across the cor-
nicles. Colour shining reddish brown. Head, thorax,
and last abdominal ring blotched with black. Cor-
nicles very small, dark, and rising from circular black
patches from the sixth abdominal segment. Antennae
slender, orange-brown with black tips. Legs shining-
orange with black tarsi, and black femoral and tibial
points; tarsi with two distinct joints; hind legs very
long. Rostrum reaches beyond the third coxee.

Apterous pviparous female.

This has very much the appearance of the last
insect. Koch says it much resembles the female of

72 BRITISH APHIDES.

Laclmus pini, except that it has no downy coat, and
that its hind legs are very much longer.

Winged male.

Incli. Millimetres.

Expanse of wings 0'340 8*62.

Size of body O-llOxO-040 2-80X1-01.

Length of antennse 0*060 1'52.

'&"

55

rostrum 0-070 1-77.

Cornicles mere warts.

Body much slimmer than that of the female. Head
and thorax disproportionately developed, whilst the
abdomen is of small dimensions. Uniform colour
shining brown, with the exception of the prothorax
or neck-ring, which is of a reddish pitchy tint.
Thoracic lobes long and large. Antennge, about half
the length of the body, brown. Legs shining orange-
brown, with black femoral, tibial, and tarsal points.
The abdomen and legs are densely clothed with yellow
hair. Wings long and narrow; membrane rather
fuscous, except as regards the stigmatic cell, which is
clear and hyaline. Stigmata ochreous, cubitus brown
and stout, the other veins dark brown. The first
furcal nervure joins the cubital nervure almost at its
extremity, and these veins do not quite touch the
cubitus. All the veins of the upper wing shade off
into broad brown cloudy stains, which extend through-
out their entire lengths. All the cells are prettily
clouded at their basal margins, but this variegation
differs from that seen in D. Groaticus. The lower wings
are not clouded.

A gentle pressure on the abdomen causes the pro-
trusion of a very large hooked penis. The curious
anatomy of this organ will be noticed in the section
devoted to the descri]3tion of the reproductive appa-
ratus of Aphides.

Towards the middle of November M. T. Lichten-

DRTOBIUS EOBOEIS. 73

stein forwarded to me numerous specimens of the
oviparous female from Montpellier. They were taken
on the branches of Quercus rohur, upon the bark of
which they had deposited numerous brown eggs, vide
Plate CIV, fig. 6. This nidus for the eggs is different
from that chosen by D. Croaticus, which deposits in
Southern France on the upper surface of the leaf of the
evergreen oak, Quercus ilex, as seen in Plate CIII, fig. 5.
M. Lichtenstein remarks " how wise of this insect to
know that the leaves of the ordinary oak will fall ! and
therefore it chooses the bark."*

The oviparous female drawn in PI. CIII was taken
from a live specimen bred with others at Mont-
pellier. It agrees well with Kaltenbach's and
Koch's descriptions. As, however, the perfect female
had not before been figured, I thought an example,
though a foreign one, would not be without its value
to the entomologist. Koch found masses of similar
eggs disposed much like those of the lackey-moth,
Gastropacha neustria. A crust composed of perhaps
one thousand encircled a bough of oak. This mass
was about an inch broad, and probably was the pro-
duce of several oviparous females.

In Germany the acorns seem to be attacked as well
as the soft stalks. According to Koch the stalked oak,
Quercus pedunculata, is preferred by D. rohoris.

In the species described by Bonnet, and which is
probably identical with the above, he states there are
both apterous and alate males. Such may be the case,
but the observation requires confirmation by others,
though this phenomenon certainly occurs in other
genera of Aphides.

Kaltenbach and Walker both include Lachnus fas-
ciatus of Burmeister in their synonyms of L. rohoris.
The former author states that he captured specimens
of L. rohoris on Pinus sylvestris and P. ahies. I think

* As Quercus ilex is not a tree indigenous to Britain it is probable
that tlie choice of nidus differs in the two countries. I am not able to
state form personal observation the precise locale affected by the English
insects.

74 BRITISH APHIDES.

it probable that he mistook this insect for Lachnus
fasciatus. As I consider this last to be of a different
species, I altogether exclude it from the synonyms
above written.

The reader is referred to a paper by M. Lichten-
stein,* in which he says that he watched the ma-
noeuvres of eight males, which discovered several cap-
tive females through some instinct which he could not
explain. These males eventually coupled with about
one hundred females, which soon disposed themselves
to lay their eggs. These eggs formed a crust of great
regularity, and were covered by a brilliant black
varnish. Sometimes they have also, he remarks, a
covering of downy matter. The eggs bear with
impunity a temperature of 12° or 15° below zero
Centigrade.

Thus, unlike most insects, polygamy is practised by
the males of Aphis. M. Lichtenstein tells me that he
has often seen the winged males waiting for the females
which gather on the same tree, which, after fecunda-
tion, place their eggs in a wonderful order on the same
branch. In the case of Dryobius roborls " a branch
may be covered for a foot or more."

Dryobius croatious, Koch. Plate CIV.
ApJiis Tohoris, Walk.

Apte7vus vivijjarous female.

Inch. Millimetres.

Size of body 0-150 X 0-080 3-81 X 2-02.

Length of antennae 0-070 1*77.

"O

55

55

cornicles 0-010 0*25.

rostrum 0-100 2-54.

"Very large. Head and thorax rather narrow. Ab-
domen broad across the nectaries. Greneral colour
isabel-brown, passing into a redder shade; head
* 'Bull. Soc, Ent. de France' (5), iv, pp. 241, 242.

DRYOBlUS CROATICUS. 75

blackisb, prothorax usually with two small black patches
succeeded on the meso-thorax by a crescentic spot.
Cornicles conical and black, rising from two circular
dark spots. Cauda rounded and short. Legs long,
particularly the hinder pair; foxy yellow with dark
femoral and tibial joints. Tarsi biarticulate. An-
tennsB slender, orange-coloured tipped with black.
Rostrum stout, and about two thirds the length of the
body.

Winged viviparous female.

Inch. Millimetres.

Expanse of wings 0400 lO'lG.

Size of body 0-210 X 0080 5-33x2'02.

Length of antenna 0*080 2*02.

jj

jj

cornicles O'OIO 0-25.

rostrum 0'060 1-52.

Body rather larger and more oval than that of the
apterous female. Head small. Thorax very large.
Abdomen oval. Colour much like the preceding insect,
dullish brown with darker thoracic lobes. • Nectaries
small and conical, rising from black patches. Cauda
obtuse. Anterior and medial pairs of legs moderately
long, but posterior pair disproportionately so. Colour
same as with the apterous female. Antennae orange-
yellow, tipped with black ; pilose. Wings relatively
short, rounded at the tips ; insertions yellowish ;
cubitus and stigmata brown. The first furcal and the
cubital veins take their origin 'from the same point,
and do not anastomose from the cubitus. Membrane
hyaline, and handsomely brocaded with rich brown,
the colour being caused by a dense net-work of faintly
pigmented hexagonal cells like those of a honey-comb.
The whole of the first discoidal and the first cubital
cells are thus covered ; and also parts of the second
discoidal, the second cubital, and the marginal cells.
A brown blotch on the stigma is carried into part of
the infra-marginal cell. The margin of the wing has
several ornamental indentures of the uncoloured mem-

VOL. III. 6

76 BRITISH APHIDES.

brane. All tlie nervures themselves are dark brown.
The lower wings are unclouded.

This pretty insect is one of the largest of the family
of Aphis, and is diffused over a large area of the Old
World. It was found by Dr. Rosenhaur inhabiting
the oaks of Croatia, whence its name. It is also found
far north in Sweden, and has been discovered in Central
Asia in the district of the Amur (Walker). As it
does not appear in Passerini's list, perhaps it is con-
fined to the cold and the more temperate regions of
the south.

This insect is not uncommon in several parts of
England. The examples figured w^ere kindly sent to
me by the Rev. N. Andrews. He obtained them by
climbing the branches of an oak at Southwater,
near Horsham. They are usually stated to prefer the
branches springing from old oak stumps. The ants
Formica ruhra and F. fuUginosa seem greatly to relish
the juice excreted from their nectaries. Late in Novem-
ber I received a consignment of these Aphides from
Montpellier, and also a leaf of the evergreen oak Quercus
ilex, on the upper surface of which some hundreds of
dark brown eggs had been deposited, — the produce of
several females, five of whose dead bodies were still
attached to the patch of ova.

The eggs, which are not strictly oval in form, but
inflected on one side, were laid very closely together,
mostly in parallel rows. They were covered with a
glutinous substance which was insoluble in water, for
they could not be detached by a camel-hair brush
filled with water. This covering seems to con-
tinue moist, since it entangles particles of foreign
matter which float in the air, and thus perhaps an
artificial protective coat is formed. M. Lichtenstein
notices these diff'erent locations of the ova in D. rohoris
and D. Groaticii>s, and considers the circumstance as
confirmatory evidence of the insects being specifically
different.

From specimens mounted by Mr. Walker — I beHeve

DRYOBIUS CROATIOUS. 77

tliat the insects named by him D. rohoris are really
D. Groaticus of Koch. But Mr. Walker's description
in the 'Ann. of Nat. History' is very obscure, and
the sense of the latter part involved. Koch does
not appear to make any very marked distinctions in
his diagnosis between the two species, but they amount
to this, that the insects differ in their general tones
of red, and the form of brocading on their wings. He
states that his description and figure of D. Groaticus is
borrowed, but he does not say from whom. He notes
that the eggs of D. rohoris are deposited on twigs,
peduncles of leaves, and on fruit capsules (" Trieben,
Blattstielen, Fruchtkapseln ").

The tinctorial character of some Aphides has been
before noticed. The English specimens of B. Groaticus,
in a very marked degree, stain Canada balsam, disul-
phide of carbon, alcohol, &c., of a fine port-wine red.
I do not notice this peculiarity in the examples of
D. rohoris sent me by M. Lichtenstein.

Lichtenstein adds another reason for believing D.
rohoris and Groaticus distinct, viz. that the males vary
as to their wings, and that the sexual forms of the
former appear about a fortnight later in the autumn
than the latter.

In France the egg of B. Groaticus laid on Quercus
ilex hatches in April, and the mother Aphis produces
young which assume wings and then they migrate,
but to what tree it does not appear. Lichtenstein
thinks they go to Quercus rohur and Q. puhescens, and
that they eventually come back again to the ilex.

In countries like England, where Quercus ilex is not
indigenous, we must suppose there is some modifica-
tion both of food plant and nidus, for oviposition.

The genus Dryohius does not appear to be repre-
sented in America by any described species. Wherever
the common Oaks of the old world, Quercus rohur, Q.
pedunculata, and Q. sessiliftora are found, the Aphides
peculiar to these trees may pretty generally be met
with. Although these trees extend over the whole of

78 BRITISH APHIDES.

Europe, except the extreme north, penetrating along
the chain of the Caucasus a considerable way into
Central Asia, they seem only to occur in America
through an artificial introduction. Probably the iso-
lating action of the two great oceans which wash the
shores of this continent has prevented the migration of
these fragile insects. Numerous Aphides, however,
there occur on the Oaks peculiar to the States of
America.

Before concluding . these remarks, I will notice an
Aphis which Mr. Walker preserved in Canada balsam,
and afterwards presented to me. He named it Jj^/iis
cistata, but I believe he never described it.

The winged form is the only one I have seen, and
therefore I cannot furnish figures. The insect has
many of the characters of Dryobius.

Dryobius cistatus, Walk.

Inch. Millimetres.

Expanse of wings 0-380 9'64

Size of body O'lSOx 0*040 3%30xl-01

Length of antennse 0*050 1'27

Thorax broad ; abdomen large and oval ; cornicles
inconspicuous. Head rather small ; antennee short,
the third joint the longest, the three following joints
about equal. Legs and wings rather short. Cubitus
stout, ending in a large clouded stigma ; cubital vein
very slender, the first furcation very fine, and the
second very difiicult to distinguish. Tlie first and
second oblique veins very thick ; the membrane
across these veins is slightly clouded with brown.

Taken at Southgate, late in June, on the Spruce-fir.
The insect is not to be confounded with Aphis costata,
Walk., which would appear to be a Callipterus.

II.

SECTION,

SCHIZONEUEIN^,* Pass.

UPPER WING WITH CUBITAL YEIN ONCE FORKED.
LOWER WING WITH TWO OBLIQUE YEINS.
ANTENNA sSx-ARTICULATE.

* Fx'om o-x«?w, to cut, and vfvpov, a nerve

SCHIZONEURIN^.

This tribal division was made by Passerini, who
thought that, as certain insects showed a more com-
plex wing venation than others, they should be grouped
separately.

The cubital vein, which is but once forked, takes its
rise from a point at some distance from the cubitus,
whence the origin of the name.

SCHIZONEURIN^. 81

Tnteoductoet.

The insects comprised in the two following tribal
groups have many characters in common. Their wing-
neuration, ringed form of antennse, and life-history,
seem naturally to separate them from the foregoing
Aphidinge.

As a general rule, these insects either roll the leaves
of trees, or build up gall-like structures on their sur-
faces, or otherwise by modifications of their foot-
stalks, construct habitations for concealment. These
masses are often of considerable size, and by their
diversity of shape afford material help towards the
identification of the species v^diich make them.

C. J. Geoffrey seems to have been the first author
who drew attention to such galls. In 1724 he com-
pared examples, and described them as tenanted by
thousands of pucerons.

Subsequently Reaumur figured roughly, but with
considerable spirit, several kinds of these galls. He
says of those on the elm tree : — " Il-y-a des annees oil
elles deviennent communement plus grosses que des
noix, et oil on troifve de monstreuses qui approchent
de la grosseur du poing." He says that each of these
constructions is the work of one single Aphis, which
becomes encircled by the " bottle-like " walls of veget-
able growth.

Von Gleichen also commented on these pseudo-
galls, and later Haliday, in the ' Ann. Nat. Hist.' for
November, 1838, made some interesting observations
on the habits of certain species which he comprised
in his new genus Eriosoma. The majority of those
named by him are gall-makers. A very similar arrange-
ment was proposed by Leach. It corresponds with
Latreille's third group of Aphides, amongst which De
Geer figured Aphis gallarum iihni, A. tremulce, A.
xylostei, and less correctly placed, Aphis gall arum
ahietis, which is more nearly allied to Coccus, and is
now known as Ghermes ahietis.

82 BRITISH APHIDES.

Before Passerini's time the number of ascertained
species was not large, but he increased the Hst of
genera, and described, in 1863, twenty-one species
inhabiting Italy alone.

Until quite recently our knowledge of the life-history
of this group was very incomplete, but within these
last ten years, through the labours of Lichtensteiu,
Riley, Low, Monell, Courchet, and Kessler, a large
mass of information has been accumulated, memoirs
have been written, and excellent drawings made. For
those who wish to follow the metamorphoses of these
insects closely, I have, at the end of the diagnosis of
species, added a Hst of memoirs in the order of their
appearance. Where so many have worked, it is not
easy to decide upon priority in discovery, and indeed
many important points have been discovered simul-
taneously in different countries.

The remarkable phases assumed by Phylloxera,
first made known by Planchon and Lichtensteiu,
have suggested a somewhat similar economy in these
higher groups. Yery little was known of the mode of
existence of the wiuged forms of the ScMzoneurince,
which issue by thousands from the galls above alluded
to ; and nothing was known of the egg, or the true
sexes, or whether hibernation took place ; or if the
constructor of the gall survived the winter, or was
hatched in spring from the presumed egg. A great
deal of this uncertainty has now been cleared away.
Professor Charles Riley, in America, has proved that
all the elm-inhabiting Pempliigince west of the Missis-
sippi give rise to perfect sexes in the autumn, and that
the impregnated egg is consigned by the female to some
sheltered portion of the trunk, where it rests secure
till the following spring. The issue from this egg con-
stitutes the stem mother (the Pseudogyne fundatrice) of
Lichtensteiu, and she is the constructor of the gall, just
as a Schizoneura mother commences the rolhug of the
leaf as a protection to her future progeny.

Professor Riley claims to have made the discovery in

SCHIZONEURIN^. 83

1875, that in Sch. americana wingless and moiitiiless
males are produced. Again, M. Jules Lichtenstein has
distinctly proved that the perfect sexes are the produce
of that second series of the winged generation which
left the galls for the purpose of dropping their young
in the bark fissures. These sexes soon pair, and at
once commence the process of oviposition of their
single large egg.

Dr. H. F. Kessler, of Cassel, through many experi-
ments and observations, showed also that the females
of the Pemphigince affecting the leaves of TJlmus cam-
2?estris retired to the trunk in the winter to oviposit,
and that speedily afterwards they died.

In 1878, M. Lucien Courchet, of Montpellier, gave
an excellent general resume of the Aphis group, and
towards the end of his memoir he fully went into the
description of " les Pucerons du terebinthe et du
lentisque." The following year he published his
' Etude sur les Galles produites par les Aphidien.'
These observations extend over more than one hundred
pages. The memoirs are embellished by six well-exe-
cuted plates, showing the structure of the galls, and
furnishing various details relating to the antennjB and
the wing-veining of the Pempliigince inhabiting these
galls.

M. Lichtenstein has patiently and successfully traced
some of these Aphides through their various stages of
development. He has employed a nomenclature to
distinguish the seven buddings or pseudo-births which
here it may be interesting to notice.

The immediate issue from the egg he styles Pseudo-
gyne^ fondatrice. To all the generations except the
final he gives the name of Pseudogynes, but to the
third series, which is winged, he gives the name of
Pseudogynes emigrantes. The progeny of these last
insects is apterous, and he styles them Pseudogynes
hourgeomiantes. The sixth generation is also winged.

* Pseudogyne, from iI/evloq, false, and ywii, female. The former terms,
Andropliore and Gynephore, have been relinquished by him.

84 BRITISH APHIDES.

The individuals are usually smaller than those of the
previous generation (No. 3), and seem already to have
commenced a degradation of form. The insects tran-
sport themselves from then' previous habitats, and
carry within them the embryos of the true sexes. To
these wing-ed forms Lichtenstein ofives the name of
'' Pseudogynes pupi/eres.^^

The last generation consists of males and females,
both of which are exceedingly small. This circum-
stance probably is the cause of their being so long
overlooked by early observers. The males are usually
apterous. Amongst the higher Aphides this sex is very
active and completely organised, but here the insects
are very simple in structure ; and from the fact that
their mouth organs are simply represented by buccal
prominences, which appear to be imperforate, they
must be quite incapable of feeding. The antennce also
are restricted in the number of their joints, which
would indicate, perhaps, a bluntness of sense as fur-
nished by those organs.

The oviparous female is also, in many cases at least,
mouthless. The abdominal cavity shows only rudi-
ments of an alimentary system, and, indeed, it is
almost wholly occupied by the single ovum, which is
not much smaller than the insect itself.

Shortly after impregnation, the female retires to some
chink or crevice under the bark, and there she dies,
often without delivering herself of her egg. In this
case the exuvias form a natural covering to the egg,
the dead body of the parent furnishing a nest for her
unhatched young. Sometimes the ovum is found
covered by the cotton-like down spun by the mother,
but in this case oviposition clearly has occurred.

The diversity of form and colour shown in these
galls is remarkable ; yet it will not be safe to infer
that because a gall is constructed on a different portion
of a leaf, or is diverse in form or colour, that it neces-
sarily proves to be the work of another insect. Never-
theless, there is often a distinctive character of nidus-

SOHIZONEURIN^. 85

coustruction effected by various species, wliicTi greatly
helps the student in separating kinds, the diagnosis
of which is obscure. This assistance also may be
claimed in distinguishing the Scliizoneurince.

Thus we have all varieties of form, from the simple
folding of the leaf to the open bladder-like blistering
of the surface, and from the pedunculated gall and
the large hollow purse of Schizoneura lanuginosa to
the complicated and fruit-like form constructed by
Ghermes, in which the excrescence exactly mimics the
fir-cone with all its bracts.

The causes of these diversions of growth and modi-
fication of structures in the leaf into such remarkable
adaption for a purpose, has engaged the attention of
many. The subject is a large one and of high interest,
but as it pertains more correctly to the science of
vegetable Teratology, only passing allusions and
remarks will be permissible in this Monograph.

It may be noted that the injection of acrid or other
juices into living vegetable tissue by Hemiptera and
other insects, produces in plants phenomena very simi-
lar to inflammation in animal organisms. Vessels be-
come turgid, cell-walls become thickened, and abnormal
growths (in vegetables often elegant instead of mon-
strous) take the place of simpler structures.

Some writers have thought that ail insect galls are
modifications of either fruit or leaf buds,* but many
forms cannot satisfactorily be referred to the malfor-
mation of originally normal buds. The " mimicry "
of fruit observable in some kinds is very remarkable,
and these probabl}' point to such an origin ; amongst
which, as an Aphis production, may be noticed the
above-mentioned gall of Ghermes abietis. It is only by
cutting into such structures that we can distinguish
their nature from a true fruit.

The oak galls, known as oak-spangles, the work of
JSfeuroterus Malpigii, and those fabricated by Sjyathe'

* Vide Mr. A. Wilson on tlie growth of galls, 'Nature,' vol. xx,
p. 55.

S6 BRITISH APHIDES.

gaster haccarium, several of which constructions may be
seen on a single leaf- vein, can only in a very restricted
sense be regarded as fruit buds. Again, some Aphis
galls rise simply out of the parenchyma of the leaf,
and such do not seem to be specially attached to any
leaf -vein. These Aphis galls have an individual
growth, and draw their nourishment through the
tissues of the leaves or stems.

M. L. Courchet* has well represented by plates the
phases of growth in galls made by the Pemphigince.
He there shows the cellular structure altered from that
of the leaf, by drawings of sections through different
diameters.

M. Jules Lichtenstein has written much on the
migratory habits of the PempJiigince.i He states that
he can trace a change of life and change of food in
several species, just as Walker did in Fliorodon Immuli,
which the last author says roves from the hop plant to
the sloe. In the same way Lichtenstein says he can
follow the migration of our elm-feeding kinds from
the leaves of that tree to the roots of grasses where
they hibernate.

More evidence is desirable before we can accept this
sudden change of economy as an undoubted fact.
More strange things certainly occur in the economy of
insects, and we may perhaps hereafter find that some
of the little known root-feeders have higher develop-
ments in known aerial forms.

The Scliizoneurince and Pemphigince have sporadic
habits, and seem to show but little forethought as to
securing future sustenance for their young. Some
species drop their young almost indiscriminately, for
they place their young often on plants so unfitted for
their nourishment, that they eventually die immature.
Prof. Eiley likens this apparent waste, or super-
abundance of life, to the wide dispersion of vegetable
seeds ; comparatively few of which find a nidus for

* Courchet, ' Etude sur les Gallos, &c.,' Montpellier, 1879.
t Stettiner, ' Ent. Zeit.,' 1877, p. 489.

SCHIZONEURlNiE. 87

germination. In the animal world it is also much the
same, for the number of mature individuals amongst
fish, for instance, does not increase, notwithstanding
that the roes of the cod and herring contain thousands
of separate ova. Some of these ova are eagerly sought
for food by other fish ; and many of the rest, if
hatched, become only larger prey for other animals.

The presence of a group of Aphides on a tree will
not therefore lead to a certain conclusion that they
were bred there, though the presumptive evidence is
strong.

There appears to exist amongst some Aphidologists
a certain confusion as to the terms pupa, egg, and
embryo ; and yet from the constitution of these bodies
there is a clear distinction. I conceive that an ovum
is necessarily composed of a vitellus with a germinal
spot, and certain membranes, which after the fertiliza-
tion of the egg and segmentation of the yolk, develop
into the embryo. The embryo therefore must be
clearly separable from the body which has developed
it. A pupa (chrysalis), from its very name supposes
an already organised form, and it is applied almost
wholly to some metamorphic phase immediately pre-
ceding the imago or perfect state. The jDroduce of
the winged female cannot therefore be a pupa in this
sense; unless two generations succeed each other, both
of which must be winged. The young dropped by the
imago has already its organs more or less developed,
and, of course, it neither contains a vitellus nor egg
adjuncts. It has, on the contrary, a greater analogy
to a maggot or caterpillar, and thus, in a restricted
sense, I have styled it a larva.

In many species of Aphidinge these larvge are born
with a delicate membrane which enshrouds the young
animal, and this with its shining, glairy, lubricating
surface, gives it an ovoid appearance, and as such has
doubtless deceived early authors.

On this account I have not used the word Piqnfer or
Pujnfer emigrant employed by Lichtenstein.

88 BEITISH APHIDES.

Prof. Riley * states that in Phylloxera the embryos
of the sexed insects remain quiescent in their
sacs for a fortnight before they emerge from their
dehcate pelHcles. This would imitate to a certain
extent a hatching, but the phenomena are certainly
distinct.

The gall-making Aphides are better represented on
the Continent of Europe than in Grreat Britain. Pas-
serini described twenty Italian species, including
Tetraneuva and Aploneura. Derbes wrote on five
species inhabiting Pistachia terebintlius, none of which
are British. Lichtenstein has added others. With
reference to conformation, Derbes remarks that in the
terebinthine Pemphiginw the ocellus or supplementary
eye occurs only in the winged forms. Some apterous
females are wholly blind, for, like cave-inhabiting
reptiles and beetles, they are cut off from light in their
closed habitations, and eyes would be useless. Derbes,
however, says the ocelli are to be found in the first
generation of others, and that these are their sole
organs of vision. f

A question may be raised whether these organs,
containing, it is true, only five or six facets, are really
referable to ocelli.

Genus XXV.— SCHIZONEURA, Hartig.

Rostrum moderately long in the adult, much longer
in the young.

Antennge with six articulations omitting the terminal
unciform process. The first and second joints very
short, the third much the longest, and in all cases either
ringed or cupped ; the fourth g,nd fifth about equal,
and also usually ringed ; the sixth joint rather shorter

* Vide seventli * Ann. Report of State Entomologist,' pp. 91, 92,
note.
t Derbes, ' Ann. des. Sc. Nat.,' 1869, p. 96.

SCHIZONEUEA LANIGEEA. 89

than the preceding, and ending witli a rudimentary
joint ; a small tubercle sometimes separating the two
parts.

Cornicles rudimentary or none.

Legs short. Tarsi furnished with two claws.

Body either powdered with a mealy substance or
furnished with w^ool-like tufts.

Wings moderately long. Cubital vein with a single
furcation, and in most species springing at some con-
siderable distance clear from the cubitus. The post-
costal nervures of the hind wings nearly straight, and
giving rise to the usual two oblique veins.

Some of the species of this genus are subterranean
as v/ell as aerial in their habits. Some are denizens of
gall-like structures, the commencements of which are
made by the insects which hatch from the ova laid the
previous season. These females are wonderfully
prolific, and become the stock-mothers or founders of
the new colonies.

ScHizoNEUEA LANIGEEA, Eausman. Plates CY and CYI,

figs. 1 — 5.

Aphis lanigera, Haus., Germar., Kirby, and Spence.
Eriosoma mail, Leach, Mosley, Haliday.

„ lanigera, Fitch.
Myzoxylus mali. Blot., Tougard, Amyot.
Schizoneura lanigera, Hartig, Kalt., Pass.
" The American blight."

Apterous viviparous female. (Queen Aphis.)*

Incli. Millimetres.

Size of body 0-070 X 0-055 177 X 1-39.

Lena:th of antennse 0*015 O'SS.

Cornicles rudimentary.

* No very satisfactory Englisli name Las been proposed for tlie imme-
diate produce of the egg of Aphis. As before stated, the hatched insect
is always a so-called female (Lichtenstein's Pseudocjyne), and she is
the founder of the whole series of generations, ending in the perfected

90 BRITISH APHIDES.

Colour dark shining brown, approaching to black.
Form oval, flat, and carinated ; dorsum domed and
deeply marked by sutures. Eyes very small. Antennse
and legs very short, black or reddish. Nectaries repre-
sented by pale papillse with a central spot. Cauda
rudimentary. Body sparsely covered with a cottony
coat which is most developed at the tail end. Eostrum
very short, only reaching to the second coxae. The
generations from the queen Aphis differ much both in
form and size from their parent. They are of various
shades of red or warm brown, and are less flattened
and longer in the body. When first born they have a
most disproportionately long and stout rostrum pro-
truding far beyond the tail. This organ soon ceases
to grow, whilst the rest of the insect rapidly develops.
The insects, when adult, exude from their pores long
silky threads, which curve round a centre, and often
form long spiral filaments, under which they hide.

I subjoin the substance of Hausman's remarks on
the habits of Schizoneiira lanigera. This species feeds
on the sap of the bark of the apple tree, Pyrus mains.
They live in dense companies and produce by the
incessant pricking of their beaks warty or spongy
swellings on the stems. Where the bark is hard, they
work under it, and insert their sucking tubes into the
softer parts, from whence they draw their nourishment.

" The woody knots are caused by the increased flow
of the sap to these wounds. In the spring and early
summer, white cottony masses may be seen hanging in
lono; tufts from the branches of the trees in orchards.
Small twigs thus attacked produce stunted leaves and
fruit, and they often die."

males and females. From a certain analogy that seems to exist, I have
usually styled her the Queen Aphis, inasmuch as like the queen bee
(Bomhiis ?), the queen wasp, and queen ant, she is the architect and also
the mother of the whole iDrood. Kaltenbach and Koch use the word
Stamviiitter, which Riley adopts in its strict translation " Stem-
mother." Founder or foundress does not well commend itself. M.
Lichtenstein uses the word fundatrix, which, though sufficiently explicit,
is rather uncouth in English. I propose, in a restricted sense. Queen
Aphis for the immediate issue from the egg.

SCHIZONEUEA LANIGEKA. 91

The popular name of this pest in England is
the " American blight." Dr. Asa Fitch^ in his re-
port on the noxious insects of New York, however,
strongly protests against the idea of its being
an exportation from America. Serville and Amyot
state that it was first seen in Europe in 1787, and
that probably it came through England from America.
Sir Joseph Banks traced its origin in England to a
nursery near London, whose owner it appears had
recently received a consignment of apple trees from
the New World. The ravages of the insect were at
first confined to the vicinity of London, but the pest
speedily spread into the Devonshire orchards, and with
such effect, that at one time the making of cider around
threatened to be abandoned. There seems to be some
doubt whether or not France received it in its travels
eastward. It was noted in the Department of the
Cotes-du-Nord in 1812, and in 1818 it was found in
the gardens of the Ecole de Pharmacie of Paris. In
1822 it was common in the Departments of the Seine,
the Somme, and the Aisne. It reached Germany in
1801 and Belgium in 1812, Throughout France to
the Mediterranean it is now common, but Passerini,
in 1863, said that then it was not frequent in Italy,
though met with in Liguria. The fact that the apple
bark is now known to harbour the egg, is a sufficient
explanation of the wide area over which the insect now
has obtained a footing. Prof. Cyrus Thomas, laying
stress upon the fact that the cultivated apple is not an
American production, states his conviction that the
pest moved from Europe to America. As, however, it
is found there on the native crab, this objection would
seem to vanish.

Prof. Riley believes that these American apj)le-
feediog Schizoneiirince are identical with the European.
From the description of the western insects I do not
doubt that they are so.

92 BRITISH APHIDES.

The Pupce.

Oval, head and tliorax very broad. Eyes large.
General colour of the insect dull brown, with yellow
antenuEe, legs, and wing-cases. The winged form of
this insect is by no means common in great Britain. In
December, when the snow was on the ground and the
thermometer stood at 21° Fahr., I found the apterous
larvae alive and plentiful on the apple branches under
the tufts of cotton. They were then crowded with
young, and had every appearance of incipient hiber-
nation. There were no traces of pupae or winged
forms.

M. Lichtenstein, however, very kindly forwarded
me pup^e and winged forms in September, 1878. They
arrived from Montpellier in an active condition, and
from these specimens I am enabled to figure the
insects on Plate CV. The pupae are but slightly
clothed with down, and the antenna are more simple
in structure than those seen in the winged insect.

Wmged viviparous Female.

Incli. Millimetres.

Expanse of wings 0*200 5 "08.

Size of body O'OSO X 0'025 127 X 0-62.

Length of antennae 0*025 0*62.

Uniform colour dusky brown, approaching to black.
Prothorax rather paler. Abdomen carinated and
ringed. Antennae short ; third joint long and strongly
ringed, the three following joints less markedly so.
Wings voluminous and rounded at their apices ; mem-
branes smoky and slightly punctured. Cubitus broad,
ending with a large trapezoidal brown stigma. Veins
black, cubital vein with a single furcation.* Legs

* The neuration of the wings of insects furnishes such valuable
characters that variation is of interest, as indicating by an increased
complexity a possible ascent to a higher type. In Scli. lanigera there
is a tendency shown to increase the venation of the hinder wings by a
divarication of the costal vein towards the apex.

SCHIZONEURA LANIGEEA. 93

sliort. Haiisman and Knapp never met with tliis
alate form, and even doubted the existence of such.
Nevertheless, M. Lichtenstein stated that in Sep-
tember they were at that time almost swarming
in the orchards of the South of France. During
their passage through the post many young were
born, and many of these under a deep lens proved
to be the non-rostrated oviparous females. Buccal
processes represented the rostrum in these very
minute insects, and the degradation was also shown
in their half-developed antennge and tarsi. In ac-
cordance with what we might expect, a rudiment
of the single egg in these young examples was alone
traceable. The colour of the oviparous female is
yellow tinged with red. The size is not more than
0'003x0002 of an inch. The eyes are very small.

In the same quill, and mixed in about equal propor-
tion, I found also young Aphides of a brown or blackish
tint. They were larger than the above, and were fully
developed with reference to their mouth-organs, the
rostra in some cases trailing beyond the tail end.
These insects can scarcely be looked on as the males,
for both Lichtenstein and Riley state that both the
sexes are non-rostrated, and incapable of taking in
nourishment. The untraced but possible presence in
the quill of a viviparous female doubtless would explain
the occurrence of these rostrated forms.

I am not able to speak from personal observation as
to the fact stated by Goureau and others, that the
European ScMzoneura lanigera descends into the soil
and attacks the apple roots in winter time. There
seems to be no good reason, however, to doubt that it
does so occasionally. Certain it is, that the apterous
larvae will bear with impunity great cold whilst
covered with their cottony tufts. I have taken them
winged in December, with snow on the ground and
the thermometer marking 21° Fahr. They were then
lively and I could trace no presence of the perfect
sexes, so that in all probability they would in this

94 BPJTISH APHIDES.

instance have hibernated on the branches and trunk.
Dr. Cyrus Thomas, of lUinois, states that the apple
Schizoneura of America certainly attacks the root and
raises knots and spongy excrescences on its fibres.
With us the apple tree is often attacked close to the
ground on what has been called the collar of the stem,
but this is not quite the same as feeding on the root.

Numerous receipts has been given for the destruc-
tion of this pest, but they all seem inefficient in the
cases where orchards extend over many acres. In the
garden much may be done by encouraging their natu-
ral enemies, Coccinella, Syrphiis, Hemerohius, and even
by intentionally introducing insects already infested by
Hymenopterous parasites. As purgative washes may
be mentioned, solution of calcium sulphide, soap suds,
solution of wood-ashes, coarse petroleum, kreosote,
and tobacco-water made by infusing one pound of the
leaf in four gallons of hot water. A single heavy
thunder-shower will do far more execution, however,
than the best efforts of the orchard keeper.

Schizoneura fodiens, BucMon. PI. CYI, figs. 6 — 12.
Apterous viviparous female.

Inch. Millimetres.

Size of body 0-055 X 0-035 1-39x0-88.

Length of antennae O'OIS 0*38.

Globose, shining. Body uniformly of a ferruginous
yellow ; slightly mealy. Head rather darker, rich
brown. Thorax and abdominal rings obscurely marked
laterally by small dark depressions. Antennae slaty
brown, about three quarters the length of the body.
The joints finely ringed or cupped as in Sell, lanigera.
This character, however, is best shown in the alate
insect. Eyes none or very rudimentary. Cornicles

X

t

SCHIZONEURA FODIENS. 95

none. Rostrum reaches beyond the third coxge.
Insect shghtly hirsute.

Taken plentifully at Haslemere from October to the
middle of November on black-currant roots, from four
to six inches underground.

Pujpa.

Has much the colour of the larvae described above,
but it is redder, the size larger, and more elongated.
Wing-cases and thoracic lobes ferruginous yellow.
Abdomen reddish. Eyes of the normal size. Rostrum
much shorter than in the apterous insect, reaching not
much beyond the first coxae.

Winged viviparous female.

Inch. Millimetres,

Expanse of wings 0*210 5'33.

Size of body 0-070x0'025 l-77xO-62.

Length of antenn93 0-030 0*76.

Body oblong. Head, thorax, and legs shining
brown or black. Eyes large and reddish brown.
Antennae six-jointed, the nail-like process not being
counted. Joints beautifully ringed. The third joint
equal to the three following taken together. Abdomen
slaty grey. Rostrum does not reach to the second
coxee. Wings somewhat fuscous, dull, and coarsely
punctured ; carried horizontally when at rest. Inser-
tions and stigma ochreous yellow. Cubital vein once
forked ; it stops short of any union to the cubitus.
Hind wings with two oblique veins.

This is the third recorded example of subterranean
habits shown by the Schizoneurince.

Sch. fodiens makes nests lined with cottony fibres,
within which twenty or more individuals congregate.

In October the larvae become very scarce, all the
young passing into pupae and winged insects.

I subjoin, in PI. CVI, fig. 9, a drawing of the some-

96 BEITISH- APHIDES.

what vermiform young, fifteen minutes after birth,
produced from the winged mother. In all probability
these are the sexed forms. Many centipedes affect
these nests ; they do not appear to molest the
Aphides in any way.

Sell, venusta, Pass., has not yet been taken in this
country. It feeds on the roots of Bromus.

SCHIZONEURA FULIGINOSA, Buchtoil, PI. CVII.

A])terous viviparous female.

Incli. Millimetres.

Size of body 0'090x0-040 2-27xl-01.

Length of antennee 0'035 1*88.

„ cornicles mere warts „

Sooty black, rather shining. Abdomen carinated
and ringed. Eyes black. Antennae sooty grey.
Whole insect hirsute, and slightly powdered with a
mealy substance. Rostrum reaches to the third coxge.

Fill) a.

Wholly black, dull, and covered with a grey, curly,
and woolly coat. Wing-cases greyish-black. Body
somewhat fusiform.

Winged viviparous female.

Incli.

Millimetres,

Expanse of wings

0-280

7-10.

Size of body

0-085x0035

2-15x0-89.

Length of antennae

0-045

1-13.

Wholly black, very hairy, slightly mealy. Antennse
with the third joint simple, that is, not ringed.
Wings moderately long. Cubitus and nervures pale
brown. Stigma long, stigmatic vein nearly straight.
Post-costal nervure (hind wing) straight, with the two
oblique veins also straight, divaricating from the same

SCHIZONEUEA ULMI. 97

point, and at almost equal angles. The abdomen has
several pores disposed upon it separate from the
cornicles.

These insects are common on Pinus Austriaca at
Weycombe, Haslemere, from early May to December.
They also occasionally visit P. sijlvestris and P. Pyre-
niaca. They range themselves in rows down the
leaflets, and at their insertions or axils the Aphis
makes small white, cottony tufts. These tufts are
frequently visited by ants.

I think it possible that Leon Dufour's Aphis pini
maritimcG, which he says is distinct from A. pini, Linn.,
may be the above-described insect. His description,
however, is too short to decide even upon its genus.

Late in November I collected, in company with the
above described, some very small examples of a bright
yellow or an orange-red colour. They were, however,
all rostrated, and yet as they contained no internal
embryos it is possible that these small individuals are
the apterous males, and I am inclined to regard them
as such. It has not yet been proved that the males of
all the Schizoneurinm are non-rostrated and incapable
of feeding.

A solution of caustic potash develops from these
Aphides a fine crimson, which, however, does not seem
to be a very stable dye. The large oily globules to be
found in these insects, under the action of the same
reagent, crystallise into radiated masses like cystine.
The presence of a colouring matter seems to approxi-
mate this and other genera to the scarlet-produc-
ing Coccus of the Cactus.

ScHizoNEUKA ULMI, Li^iii^ PI. CYIII and CIX, fio-s.

1—4.

Apliis folioTum, De Geer.

Schizoneura ulmi, Kalt., Koch., Pass., Riley, Thomas.
„ Americana, Riley (?).

98 BRITISH APHIDES.

Apterous Queen Aphis.

Incli. Millimetres,

Size of body 0-095 X 0-045 2-41xl'13.

Length of antennae 0-012 0-30.

„ cornicles rudiraentaiy.

Broader and larger than her offspring, even when
they are adult. Covered with a cotton-like fibre.
When denuded, flat-oval, sometimes almost circular.
Dorsum domed and ringed. Colour variable with age,
from pale green to dark olive ; mottled. Four series of
longitudinally-arranged pores occur down the back,
each of which gives rise to the cotton-like fibres under
which the insect conceals itself. Head and thorax
very small and black. Antennas and legs very short,
and black also. The latter when contracted under the
body quite hidden, as in Coccus. Rostrum very short,
reaching only to the second coxse. Antennae degraded
in type, and usually restricted to at most five joints.
In later generations these organs regain their full
development.

The leaves of Uhnus suherosa are attacked by this
insect immediately after she leaves the egg. She
commences her punctures under the leaf almost
directly it unfolds from the bud, and she causes it to
blister into numerous cavities, within which she
nestles. Shortly afterwards the leaf curls from above
downwards into a roll of a sickly yellow colour.
Within this roll a large number of young are born.
They are of a lengthened form, and of a lively green.
After several months they develop wing-cases and
become pupgo, from which the images of the first series
(" Pujnferes emigrantes,^^ Licht.) emerge in turn, and
take wing for the purpose of dropping their progeny
on other trees and branches.

These young are born in the form of yellow ova,
and might be almost mistaken for such, except from
the existence of two black eyes which are sufficiently
perceptible. The casting of a delicate membrane

SCHIZONEURA ULMI. 99

permits the disengagement of the Hmbs, and the rapid
growth of a golden yellow pilose coat. The growth of
this covering is remarkable under a high microscopic
power. The hairs shoot out like magic from minute
papillae, and in about half a minute the yellow shining
body, which rapidly pulsates during this process, is
invested with the setose covering alluded to. On
one occasion I counted the rate of these births, and I
found that two, on an average, were born per minute,
and that for a considerable time.

When first born the investing membrane seems to
have a lubricating substance upon it. This must have
some tenacity also, for some of these young, just com-
mencing to walk, carried off on their backs several of
their less aged sisters. After this multiplying process
has continued for an hour or more, it is not to be
wondered that the imago should much change her
shape.

These young, the produce of the first generation of
winged females, have long rostra.

The pup^ are long, pale green, and clothed with
white filamentary matter, like the larvae.

Winged vivijmrous female.

Expanse of wings
Size of body
Length of antennge

Long oval, wholly black. Abdomen much ringed,
and brownish. Antennse with third joint very long,
longer than all the other joints taken together; third and
fourth joints cupped or ringed. Rostrum short. Eyes
black and prominent. Abdomen furnished with nume-
rous white filaments, mostly of a cork-screw form, which
is apparently caused by the extrusion, from minute
pores of silky matter, in a plastic condition. These
filaments are most abundant tovv^ards the tail end.
Wings broad and rounded at their tips ; membranes

Inch.

Millimetres.

0-280

7-11.

0-075x0030

1-89x0-76.

0-040

101.

100 BRITISH APHIDES.

ratlier smoky in tint. The cubitus and other veins
black ; stigma broad and dilated posteriorly. Legs
moderately long and black. The wings are generally
carried pentwise, but sometimes the horizontal position
is assumed.

Some years this insect is very plentiful throughout
June and July on the common Elm, TJhnus camjpestris.
On shaking the boughs, abundance of the flocculent
matter falls, mixed with numerous colourless globules.
These have been previously voided from the anus of the
insect, and being dusted with mealy matter, do not soil
the surfaces on which they roll. They have the appear-
ance of grains of bright silver sand, and freely run on
glass without wetting it. If breathed upon, however,
they burst and leave only a spot of liquid, together with
fragments of what would appear to be a film or delicate
membrane. These globules are not alone produced
by Sckizoneurci, but they seem to be a usual accompani-
ment to those Aphides which nest in close covered
structures.

It is suggested that by the isolation of these globules
the insects are not contaminated by their own excreta.

Prof. Riley describes an elm Aphis under the name
of Schizoneura Americana, and which be thinks is
distinct from Scli. ulmi of Europe.* One peculiarity
of this insect is, that it rolls the leaves from below
upwards, from which I gather that it feeds on the
upper surfaces instead of on the lower, as with us.
There appears also to be some slight variation in the
wing-veining, and in the occurrence of four instead of
three booklets on the lower wings. f

In ' Notes on the Aphididse of the United States,'
Messrs. Riley and Monell have given a full and interest-
ing account of this insect, and they may be congratu-
lated on their success in tracing the steps of develop-
ment throughout the six generations which intervene

* ' Bulletin of Survey,' vol. v, No. 1, 1879.
. t Those Britisli insects wliicli I Lave examined sliow also four liook-
lets on the loAver wings. — G. B. B.

SCHIZONEURA ULMI. 101

between tlie exclusion from the egg and the appearance
of the perfect sexes.

With slight variations these stages of development
may be regarded typical of the genus.

Numerous workers have, however, been on the same
track, and have greatly added to our knowledge ;
amongst whom may be mentioned Messrs. Lichtenstein,
Courchet, Kessler, and Cyrus Thomas, of Illinois.

Briefly the life-history is comprised in the following
remarks :

A careful examination towards winter of the crevices
of the bark of such elm trees as have been infested
during the past summer will sometimes lead to the
discovery of small, dull yellow or brownish ova about
0*05 millimetre in length. Some of these eggs will be
found free of all downy matter, others are wholly con-
cealed by such, whilst here and there will be seen some
partially enclosed, and protected by the exuvijB of
their dead mothers, who have died before accomplish-
ing their task of oviposition.

These impregnated single eggs — for only one is laid
by each individual — hatch and produce the queen Aphis,
stock-mother, or fundatrix of Lichtenstein. These
commence the distortion of the young leaves in spring.
They moult their skins about three times, and after
the expiration of a few days, dependent on temperature
and moisture, they begin to people the cavities of the
curled leaves with young of the second series.

Some of these migrate to other leaves, and eventually
the third generation arrives, which goes through the
pupal stage, acquires wings, and then spreads over
other trees.

This last is the " emigrante " stage of Lichten-
stein. The life of these winged females appears to be
but short. They produce about twelve young each at
intervals perhaps of half an hour on the average, and
then shortly after they die.

According to Prof. Riley, the American ScMzoneura
ulmi is not so prolific as the European.

102 BRITISH APHIDES.

I have often witnessed tbe rapid births of these
insects. These young, which form the fourth genera-
tion, are very active, they run swiftly and have long
rostra, by which they suek up the sap, and thereby grow
rapidly. They course up and down the elm twigs and
show their presence by the plentiful tufts of cotton
with which they powder the leaves. In Belgium, near
Spa, I have seen the elms hoary with this cottony
substance, and then the shaking of a bough produces a
shower of liquid exudation and white flocks.

The fifth generation appears also to be apterous;
but the sixth once more shows pupal forms and
discloses the corresponding imago towards the end of
June and throughout July.

These are ''les pupiferes " of Lichtenstein. Except
that they are usually much smaller, they do not greatly
differin appearance from the earlier alate insects. They
roam far and wide on the wind currents : those which
discover suitable quarters establish themselves. Ac-
cording to Riley, they particularly choose the bark,
and there they give birth to the seventh and last gene-
ration — the perfect sexes. These are very diminutive,
and on that account for a long time they were over-
looked by Entomologists. They are of various shades
of colour, from bright yellow to orange and red.

The males, so far as my experience goes, are born
with rostra, but these organs disappear after a moult.

This degradation of type in the sexes is remarkable,
and it has been commented upon by Lichtenstein,
E-iley, Low, and others. It also obtains in other species
of Fem^liigincB and Schizoneurince.

The oviparous females are, on the other hand, born
mouthless, and thus are incapable of obtaining nourish-
ment. The ovum nevertheless enlarges, perhaps from
the imbibition of w^ater through the parent.

After retiring into the hollows of the elm bark, the
females lay their single eggs, or else die without ex-
truding them, which nevertheless live, as before
noticed, to recommence the cycle of the ensuing year.

SCHIZONEUKA ULMI. 103

Lichtenstein says that tlie produce of these winged
females descend into the ground, and that they hiber-
nate at the roots of various grasses.

If I understand him rightly, he maintains that the
cycle of these insects' lives spreads over two years,
and the sexes are not seen till the second season. On
the other hand. Prof. Eiley says that this habit is not
in accordance with his own or M. Derbes observa-
tions on Pemphigus cornicularis.

At present this subterranean habit is so far an open
question that it requires more attention than has been
bestowed by natiu'alists upon it before it can be said
to be scientifically proved.

In the State of Mississippi Schizoneura Americana
sometimes infests the Elm trees so much that Prof.
Eiley has seen a matted mass of dead insects under the
trees from three to four inches thick. This decaying
mass was the food of numerous other insects.

During someyears the English Aphides are sufficiently
plentiful, but occasionally they are difficult to find even
in their old haunts. Such was the case in 1879 at
Maiden, in Essex, when Mr. E. A. Fitch could only
send me a few winged forms collected from rolled elm
leaves in the month of October, These were so small
that they might almost be taken for another species.
It is probable, however, that they were the winged
mothers ready to transport the perfect sexes to the
places of oviposition. Their expanse of wings was
only 0*155 of an inch against the nominal 0"310 of an
inch, which last measurement represents an insect born
in June.

I have occasionally plucked leaves of the Elm rolled
fro7n helotv iqnvards, but I could not discover any
unusual specific distinctions in the insects inhabiting
them.

I quote M. Lichtenstein's words with reference to
the migration of these Aphides. " Ce qu'il y a de plus
curieux, c'est que la Scliiz. Americana ne quitterait pas
I'ormeau et efiPectuerait ses sept changemeuts sur le

104 BRITISH APHIDES.

meme arbre, tandis que cliez nous, bien certainemenfc,
non seulemeut pour I'espece actuelle, mais pour toutes
celles que je cite, il y a migration, et pas un puceron
ne reste sur I'ormeau apres le mois de juillet. Au
moinSj je n'ai jamais pu en trouver."*

ScHizoNEUEA LANUGINOSA, Hartig. PI. CIX, figs. 5 — 10.

Reaumur, Germar, Ealt., Koch, Pass., Kessler.

Mimaphidus ulmi, Rondani.

Apterous viviparous female.

Inch. Millimetres.

Size of body 0-050 X 0-025 1-27 X 0-63.

Length of antennae 0*020 0'51.

Form long-oval. Colour black, smooth, clothed
with cottony filaments. Eyes very small. AntenntB
short, and often showing but four articulations. Ros-
trum black, reaching to the second coxte. Legs short.

Winged viviparous female.

Inch. Millimetres.

Expanse of wing 0-230 5-84.

Size of body O'OSSX 0-020 1-39 X 0-51.

Length of antennjs 0*020 0-51.

Black. Antennie strongly ringed and very short,
six-jointed. Abdomen at the apex furnished with
white filaments. Rostrum short, cornicles mere pores.
Wings hyaline. Stigmata large, blackish green. Veins
black and very slender.

This ScJiizoneura forms gall-like masses at the ends
of the twigs of JJlmiis camipestris and U. suherosa.
They are densely hairy, and vary in size from a small

* ' Extrait de la Feuille cles Jeunes Naturalistes/ Aout et Septembre,
1879.

SOHIZONEUEA LANUGINOSA. 105

nut to masses as large as a green fig, or even larger.
TLej are corrugated longitudinally, and of a green or
brownish-green colour. These curious masses are
formed by the Queen Aphis — the produce of the egg.
She makes her punctures near the mid-rib of the leaf,
and there these distorted masses occur either single,
double, or else grouped in bunches. On account of
their size and hairy character they may be easily dis-
tinguished from the smoother galls made by Tetra-
neura uhni. The two galls may, however, be found
simultaneously on the same tree.

They attain their full size in August, at which time
they contain thousands of plant-lice, both apterous and
winged. A small opening is formed usually at the
summit of these galls, from which the winged mothers
make their escape as soon as they feel the imperative
calls for migration.

In 186G, Mr. R. McLachlan, travelhng in the South
of France, gathered a number of such galls, which were
in extreme profusion; trees twenty feet high being one
mass of galls. He remarks, " I collected some small
branches, intending to bring them home, but they
made such a mess from the liquid in the galls that I
was forced to throw them away."*

I have received living insects from M. Lichtenstein,
at MontpelHer, which in all respects seem to be identi-
cal with the British species.

I have also been kindly furnished with similar galls
by Mr. Brady, from Rainham in Essex. The bodies of
the pup^e were full of embryos, which shows that the
change of form and moulting does not interfere with
the process of internal budding, since the young would
not be born until the parents had passed'into imagos.
The largest galls I have seen w^ere gathered by Mr.
Thomas Brown from Elms near Cambridge, in the
year 1871. I obtained these through the late inde-
fatigable naturahst, Mr. Edward Newman. The largest
of these measured 3-0 X 2*5 inches (=:73x66 milli-
* Vide ' Ent. Montli. Mag./ vol. iii, p. 167.

106 BRITISH APHIDES.

metres). They were so remarkable that I figure them
from the outlines furnished by Mr. Newman himself,
but necessarily much reduced from their natural size.
I also received from Mr. E. A. Fitch a mass of con-
torted galls gathered by him at Maiden in Essex.

These galls take various shapes ; but no certain
inference, I think, can be made as to any diversity of
species simply from the different forms of their
habitations. When cut open these galls showed the
midrib and other veins of the leaf greatly modified
and expanded. At first we might be disposed to think
that the insect had eff'ected a separation of the upper
membrane of the leaf from the lower, but an examina-
tion of the interior of the gall shows that these veins
form a sort of framework of ribs to the whole cavity,
arching it over, and giving us more the idea that the
leaves had united at their edges to form the hollow
spaces. The interior is lined, as is also the outside,
with a velvet-like ipile, and the walls of the cavity are
more or less blown up into hemispherical bubbles.

The second winged forms, which appear late in the
autumn, and which probably produce the perfect
sexes, are smaller than the winged females, which
appear early in June. The former only are figured in
the above-mentioned plate.

The occurrence of Sehizoneura lanuginosa in England
is more plentiful in some years than in others. During
the cold wet season of 1879 scarcely an example could be
found on those Elms which usually formed their resort.

Bonnet noticed these galls more than one hundred
years ago, and tells us that in his time they were em-
ployed in Persia, China, and the Levant, under the
name of " baizonges," to assist in extracting the scarlet
dye from the cochineal insect. Bonnet showed that
these " vessies " were produced by an Aphis, and not
by a Cynips or gall-fly as supposed.

Passerini remarks, with reference to the liquid
obtained from these pseudo-galls, " Rustici nostri
liquore gummoso-saccharino in gallis collecto utuntur

SCHIZONEUrvA COEXI. 107

ad curandum vulneribus sub nomine olei Sti. Joannis."
It is not unlikely that tlie astringent cliaracter, coupled
with the viscosity of this liquid, may have some healing
effects, and beneficially exclude the air from open
wounds.

M. Lichtenstein has hazarded the supposition that
Sch. veimsta of Passerini is the underground form of
Sch. lanuginosa. Although the migration of Phylloxera
vastatrix from the root to the branches of the vine is
fully proved, and I have shown that both aerial and
subterranean forms exist in Schizoneura fodiens, a too
hasty generalisation should be avoided. A close and
pains-taking observation will alone justify the fusion
into one of these two apparently well-marked
species.

ScHizoNEUKA coRNi, Fah., Schr., JIaus., Kalt., Pass.,
Licht. PL CX, figs. 1—4.

Scliizoneura vagans, Koch.
An^cia corni, Koch.

Oval, flat, dull black. Abdomen brownish ; legs paler.
The first brood appears in England about August upon
the white cymes of the dogwood Cornus sanguinea. In
Germany they appear in greater plenty ; and late in
August and September, when they assume wings, Kal-
tenbach says that the air is so full of them they fly into
the eyes, nose, and mouth, to the great annoyance of
the traveller. At other times they swarm like gnats
in the slanting rays of the sun.

Winged vivijmro^is female.

lucli. Millimetres.

Expanse of wings 0'250 6"35.

Size of body O'OSO X 0*030 2-02 X 0-76.

Length of antennee 0*040 I'Ol.
VOL. III. 8

IDS BRITISH APHIDES.

Yelvety-black, with tlie first tliree abdominal and
also tlie apical rings ferruginous. Eyes dark-brown.
Antennae, legs, and apex of abdomen hairy. Antennse
much tuberculate. Rostrum reaches to the third coxas.
Wings with a smoky membrane, and covered by
minute punctures. Cubitus strong, with yellow
insertions, and ending in a large brown stigma, the
fore border of which has a black internal rhomboidal
spot. Other veins black; the cubital vein does not
quite reach the cubitus.

Koch gave the name Sch. vagans to this species,
from the wandering habits of the winged form. Riley
describes an American Aphis with the same habit
under the name of Pemphigus vagahundus.

In the autumn the English insect may be found
mixed with Aphides of other kinds on a variety of
trees. I have taken them on the medlar, the honey-
suckle, the plum tree, and the oak. Late in Novem-
ber the winged females continue full of embryos, most
of which would appear to be dropped on plants unsuited
for the food of the young Aphis. Professor Riley
draws a parallel between the profuse dispersion of
seeds into sterile places and the apparently aimless
deposits of young by many of these insects,*

When the food plant is in abundance the insect is
much spread in proportion, and this abundance has
been thought to explain the myriads of Phylloxera
vastatrix which now devastate the vines of France and
Italy.

I cannot see either in Koch's diagnosis or his
figures any sufficient reason for separating Sch. corni
from this genus, for I believe, with Passerini and
Lichtenstein, that Sch. vagans is really Hausman's Sch.
corni, and therefore I place it as a synonym. Thus
Koch's new genus, Anhoeciai to me seems to be unne-
cessary. ^

M. Lichtenstein, with his usual liberality, sent me

* Vide ' Notes on the Apliididse of the United States,' Riley and
Monell, Washington, Jan., 1879.

SOHIZONEURA CORNI. 109

several living- winged individuals of Sch, corni from
Montpellier. They arrived on the 5tli of December,
and on their journey they gave birth to several yellow-
ish-red and greenish young. M. Lichtenstein regards
these as the true males and females, and very probably
they are such. Nevertheless, a careful examination
under a high magnifying power did not show to me
either any included egg or the usual male organs. As
the insects, however, could not have been many days
old, these structures may not have had time for de-
velopment. One argument in favour of these young
being the two sexes is, that they are very different
in form and colour from the rest. The presumed
male is rather linear, and cylindrical ; shining yellow,
with well-developed antennse and prominent eyes.
The female is stout, oval, green, and has eyes much
smaller. Ten of these forms were examined, and all
were distinctly rostrated. The sizes were, for the
male 0-027 XO'Oll inch, for the female 0-024x0-013
inch.

M. Lichtenstein thinks it probable that the Schizo-
neurlncB have both aerial and subterranean forms ; that
is, that they migrate from the roots of grasses and
wheat to the branches of trees. In this manner he
thinks the Continental Sell, venusta of Pass., which
affects many different kinds of grass roots, may
prove to be the winter form of Sch. ulmi or /Sch.
lanuginosa. I have no experimental proofs of such
migrations from tree to tree to off'er; and Professor
Piley is inclined to deny altogether the fact of this
migration.

The before-mentioned Pempliigiis vagahundus is
not likely to be met with in this country ; for it is
said to breed on the cotton- wood of America, on the
leaves of which it forms large cockscomb-like galls,
and also to be unable to subsist on any other trees.
Nevertheless, in Missouri, the winged females may be
plentifully taken at the fall of the year, on numerous
dissimilar plants, on which, like their European allied,

ilO BRITISH APHIDES.

sisters, tliey wastefully drop their young, and earn
their specific name vagabundus.

The States of America and Italy furnish several
interesting Schizoneurince unknown in Britain.

III.

PEMPHIGIN^.

UPPEB WING "WITH CUBITAL VEIN SIMPLE.

LOWER WING GENEEALLT WITH TWO OBLIQUE VEINS.

112 BEITISII APHIDES,

PEMPHIGIN^.

The habits of this Tribe are very similar to those of
the preceding ; that is, they are gall-constructing,
and in some instances they are partly subterranean.
Although the known species are not very numerous, a
considerable literature exists on the group, which is
chiefly of modern date. This attention bestowed is
partly due to the obvious distortions produced by these
insects on the leaves, or their foot-stalks, of various
trees. These curious excrescences and abnormal
growths take a great variety of form, and to a certain
extent show sach individual characters as materially
assist in identifying the species which construct them.
The characters of some species are not very sharply
defined, and they would not be very easy to identify
if the life-history and various methods of building
their habitations were ignored.

PEMPHIGUS. 113

Genus XXVI.— PEMPHIGUS,* Hartig.

Rostrum as in Schiz'oneura.

Antennge short, with six joints, omitting the nail-
like process. Third joint about equal to the three
following taken together. The third, fourth, and fifth
joints commonly ringed ; the sixth joint longer than
that of Schkoneura.

Cornicles wanting.

Wings with no furcated cubital vein ; this vein, as in
the last genus, being unattached to the cubitus ; stigma
large and trapezoidal ; the two oblique veins usually
start from the same point. The posfc-costal nervure
of the hind wing somewhat angular, from which angle
the two oblique veins spring.

Legs short, particularly in the apterous forms.

It is to be noted that sharp characters cannot always
be drawn from minute differences in the antenna!
joints. These organs become developed during the
progress of the insect towards its imago state, for here
it is that the climax seems to be reached and not in
the true sexes. These last suffer a degradation in
type, which appears in the stunted antennse and total
absence of efficient buccal organs.

Neither can any safe characters be made from the
deflexed or vertical position assumed by the wings
whilst at rest. The horizontal and pent-wise position
has been before noticed in some of the foregoing genera.

Pemphigus fusgifrons, KocJi. Plate CX, figs. 6 — 9,

Amycla fusci/rons, Koch.
Fem])higus JBoyerii Pass.

„ ?:ece maidis, Low. ?
Ai^liis radicum, Boyer de Fonscolombe ?

* From TTfjit^if, tyoe, a bladder or pustule.

1 14 BEITISH APHIDES.

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-080 X 0*040 2-02 X 1-01.

Length of antennse 0-017 0-43.

Long oval, golden yellow. Head with two dusky
spots on occiput. Antennae five-jointed, the fourth
the longest. Abdomen naked or but slightly clothed
with cottony fibre, and furnished with small marginal
punctures. Nectaries none. Rostrum reaches to the
hind coxa. Eyes conspicuous and brown. Antennge,
back of the head, and legs fuscous.

Fupa.

Long oval, yellow. Head, antennse, and wing-
cases fuscous. Abdominal hind rings furnished with
numerous tufts of stiff fibre like spun glass, each tuft
issues from a distinct glandular opening placed not
at the sutures but in the midst of the body-ring.

Winged viviimrous female.

Inch. Millimetres.

Expanse of wings 0*220 5-58.

Size of body 0-080 XO'OSO 2-02x0-76.

Length of antenna 0-030 0*76.

Head and thorax black. Antennse six-jointed, not
counting the nail. The third joint the longest, which,
w^ith the following joint, is slightly ringed. Abdomen
naked, fuscous, or dirty green ; nectaries none or im-
perceptible. Eyes brown. Antennse and legs fuscous.
Wings with greyish membranes, slightly punctured ;
stigma fuscous, with darkish stripes at their apices ;
cubitus, other veins and insertions, dark brown. In the
hind wings the two oblique veins form with the costal
nerve a tridental fork.

The Queen Aphis (fundatrix) is large, pale lilac,
with green spots, indicating the embryos. Head, legs,
and antennse very small ; whilst the abdomen is very
arge. Antennse restricted to four joints.

PEMPHIGUS FUSCIFEONS. 115

The true sexes are very small and non-rostrated.
Lichtenstein says they copulate soon after birth and
then die. He, like other authors, speaks of what he
calls the monoecious character of Aphides, and asks,
'' Is there any other instance amongst insects known
in which the male and female proceed from the same
egg ? Is the difference between a monoecious and
dioecious egg recognised? "

In the month of June I received from Moutpellier
numerous insects for comparison, which M. Lichten-
stein regarded as Amy da fuscifrons, of Koch. There
seems, however, to be some points of difference be-
tween the English and the French insects. The winged
foreign examples are smaller than the British; their
antennas are less ringed, and they have a peculiar,
though slight, clouding throughout the whole length
of the wing veins. I am unable to say, from my
present information, whether these differences are only
climatal.

Pem])liigus fuscifrons may be taken plentifully at
Haslemere at the roots of Hieracium murorum and H.
sahauduvi, and also at the roots of Lactuca. The
insects form cavities in the earth which are sparsely
lined with cotton. The imagos rise to the surface of
the ground during the months of August, September,
and even as late as November. The females, to the
naked eye, have a sooty hue, more especially as regards
the wings, which, unlike other Aphides, are carried
horizontally. Koch found Amy da fuscifrons plentifully
feeding at the roots of the oat, Avena sativa. This
insect certainly feeds on a variety of plants.

Some remarks may here be made on the maize
Coccus of Leon Dufour, inasmuch as Dr. Franz Low, of
Vienna, includes P. fuscifrons amongst the synonyms
of that insect.* Dr. Low says that the Aphis which
often causes such great damage to the crops of Indian
maize in Hungary and Styria has been long known to

* Dr. Franz Low, ' Ueber eine dem Mais scliadliclie Aphidenart,'
p. 6; Nov., 1877.

116 BRITISH APHIDES.

science. He states that it was first erroneously de-
scribed by Leon Dufour in 1824 under the name of
Coccus zece maidis.^ But it is difficult to suppose that
the clever and accurate anatomist Dufour was misled
as to the characters of Coccus and Aphis. There is,
therefore, room to doubt the identity of these insects,
and the more so, that a maize Coccus exists.

Low also states his belief that other authors have
described the insect under different names. Thus he
says Boyer de Fonscolombe,t in 1841, described it under
the name oi' AjyJiis radicum; and that Passerini, in 1856,
provisionally {pro parte) ranged it under his synonym of
Pemphigus Boyeri, but did not know of its habitat at
the roots of maize plants. Again, Low considers that
the following insects are identical with this maize
Pemphigus, Amyclccfuscifrons, Endeis rosea, and Endeis
hella of Koch. He gives as additional maize-feeders
Aphis zece, of Curtis, A. maidis, Fitch, Sipha maidis,
Pass., and A. maidis, Bonafrons. He says the last-named
insect more nearly approaches the genus Siphonophora.
Passerini adds to these Toxoptera graminum and Tychea
setasia as infesting Zea Mays. Low's insect fairly
agrees with the British specimens of P. fuscifrons
which I have seen, but he says the wings are, in repose,
carried pentwise, covering the body (dach-formig).

Whilst I have no doubt that the above English insect
is the same as that described by Passerini as P. Boyeri
and synonymous with Amy cla fuscifrons , it appears to me
that, if Koch's name is to be changed at all, it ought
to revert to that given by Fonscolombe, viz. P. radicum;
that is, assuming that the last insect is identical with
the two former. I prefer leaving it as Koch described
it ; for Fonscolombe's insect might prove to be Forda.

Passerini found Pemphigus fuscifrons feeding at the
roots of numerous kinds of graminese, Zea, Sorghum,
Panicum, Oryza, Eragrostis, Lolium, Coix, &c.

* ' Ann des. Sci. Naturelles,' 1824, t. ii, p. 203.
t • Ann. des Sci. de France,' t. x, 195, 1841.

PEMPHIGUS BUESARIUS. 117

Pemphigus bursaeius, Hart. PL CXI, figs. 1— -7, and

CXIII, figs. Q—S.

Aphis hursaria, Linn., Fab., Scli., Kirby and Spence.
Eriosoma populi, Mosley.
ApJiioides bursaria, Rondani.
Pemphigus hur sarins, Kalt., Koch., Pass.

Apterous viviparous female {Queen Aphis).

Incla. Millimetres.

Size of body O'llOx 0-080 279 X 2-02.

Length of antenna 0-015 0-38.

Large, oval, dusky green, body-rings well marked.
Head fuscous. Antenna very short. Legs dusky and
very short. All the somites are garnished with from
four to six white woolly patches. Tail none. Rostrum
very short. The antenna are only partially developed,
and are composed only of four joints.

The generation which succeeds this is flatter and
smaller; smooth, darkish green, and furnished with
short cotton-like threads. The antennse, though some-
what more developed, still only show four articulations.
Eyes very small.

Pupa.

This has a longer form, and is of a pale greenish
hue. Head, wing-cases, and legs, somewhat smoky.
The sides of the abdomen and the last few rings have
white mealy patches. Towards the tail this farinaceous
matter appears in greatest abundance. The lateral
edges also have similarly disposed white spots,

« Winged viviparous female.

Inch. Millimetres.

Expanse of wings 0-300 7-62.

Size of body O'llO X 0'040 2-79 X I'Ol.

Length of antennas 0*040 1-01.

118 BRITISH APHIDES.

Body wholly black, with irregular patches of mealy
matter, which also powders the wings. Head small
and round. Antennae six-jointed, the third, fourth,
and fifth being dissimilarly ringed, the sixth smooth
and ending with a nail. Abdomen long-oval, smooth,
cylindrical, and mealy. Legs short and black. Eyes
moderately large and black, AYings with smoky mem-
branes. All the veins are black. Cubitus and stigma
smoky grey. The two oblique veins of the fore wings
take their origin from almost the same point of the
cubitus. The third vein does not touch the cubitus
by one third of its length. In the hind wings the
oblique veins so unite to the costal nerve as to form a
kind of trident. All the veins are black.

These winged females are very prolific, bringing
forth oblong, smooth, yellow-coloured young, which
appear like ova at the time of their birth. Six of
these young were born and disengaged themselves
from their enveloping membranes within the short
space of an hour and a half.

I have gathered galls in plenty during the month of
June, formed by swellings of the petioles of the leaves
of Populus nigra and P. dilatata. They occur in many
parts of England. I have picked them at Haslemere,
Chichester, and Walthamstow. They are also common
in the South of France, and at Spa in Belgium. These
purses are pear-shaped or long-oval, with small open-
ings at their summits, which gradually widen and
have usually a number of pink corrugations at their
edges.

Towards the beginning of July the winged females
come out of their pupae, and on the access of the
sun's rays issue forth in great numbers in order to
spread elsewhere. When cut into, these galls disclose
a single chamber, formed of thick fleshy walls ; which
a high magnifying power shows to have a dense
cellular structure. The cavities contain a quantity of
those previously noticed spherical globules, which are
of a mucilaginous nature.

PEMPHIGUS BUESARIUS. HO

Kocb. was aware that these habitations were the
work of the stem-mother.

Notwithstanding the concealed hfe of these insects,
they are by no means secure from the attacks of
enemies. Minute A]yliidivoroiis IchneumonidcB succeed
in introducing their eggs, and the larvse from these
destroy the inhabitants and speedily cause the break-
ing up of the gall. After the galls are vacated they
form a nidus for a small fungus which speedily con-
verts them into dry dust.

M. Lichtenstein obligingly forwarded me in July
excrescences from the Poplar, which rise from the
more woody portion of the twig. Though constructed
almost side by side with the pyriform galls, they differ
much in form, being more spherical and rugose on
their surfaces.

M. Lichtenstein, partly from these differences,
hesitates to accept the pear-shaped construction as
the work of P. bursarius. I am not aware that he has
yet published any memoir on the specific differences
of the insects fabricating these two descriptions of
galls, but he suggests to me that the woody spherical
gall is the work of P. bursarius, smd. that the pear-shaped
excrescence is fabricated by an undescribed species,
for which he proposes the name of P. injriforT^iis.

Reaumur gives a good woodcut of a sprig of poplar
on which five galls are represented, two rising from
the stem, two from the petioles of the leaves, and one
from the midrib.^' These he distinguishes in his
description of the figure thus : — " La figure represente
un bout de branche de peuplier charge de plusieurs
feuilles ; galles que partent des pedicules des feuilles
(P. lyijriformis, Licht.), autres galles qui tirent leur
origine immediatement de la tige (P. bursarius^ Licht.),
et une galle d'une feuille (P. marsupialis).^^ Reaumur
groups these as the work of a single species, and I
believe all authors up to the present time have simi-
larly regarded the question.

* Reaumur, 1. c, t. Hi, pt. xxvi, fig. 8,

120 BRITISH APHIDES.

Kirby and Spence long ago spoke of " Aphis hur-
sarla, wliicli, with its brood, inhabits augula.r utriculi
on the leaf-stalk of the black poplar, numbers of which
I have observed on the trees by the roadside from Hull
to Cottingham." Kaltenbach says, '" Die Gallon sind
an den verschiedenen Stellen auch verschieden gebil-
det." The following is the substance of his remarks
on P. hursarius. The galls are differently constructed
in different situations. The stem-mother which has
survived the winter forms a swelling on the leaf-stalk
(Blatt-stiel), which quickly rising on all sides forms a
kind of groove in which the insect lies. The edges of
this cavity draw themselves together over the creature,
and at last wholly close her in. Sometimes two
females work on the same foot-stalk, and their com-
bined action modifies the form of the gall.* Koch
gives two positions for the gall, one is constructed, he
says, on the midrib of the leaf, and the other less fre-
quently on the ends of the leaf- stalk ; in these galls the
openings are found at the sides : " Seltener bilden sich
am Ende der Blatt-stiele solche Blasen." Passerini
says : — " Intra gallas petioli et costee foliorum Pojmli
nigne, Maio, Junio, et serins in gallis terminalibus
ramuorum ejusdem speciei."t

I have compared the inhabitants of both galls, but
although I see a difference in size of the insects, and a
modification of the ringing of the fifth antennal joint,
I do not feel competent to decide from these characters
that they belong to different species. M. Lichten-
stein's experience in these special genera will doubtless
set the point at rest in one of the future papers he has
promised on the Pempliigians. As the pseudo-gall
itself is characteristic, I have figured it for the pur-
pose of drawing the attention of British entomo-
logists, yet still provisionally retaining it as constructed
by P. hursarius.

* Kalt., ' Mou. der Pflanzenlause, p. 183.
f Pass., ' Aphid. Italicse,' p. 75.

PEMPHIGUS BURSAEIUS. 121

Koch's* figures of P. bursarius are not happy.
Tlieir wing-veining is inexact and defective in drawiDg.

M. DerbeSjt and likewise M. Lichtenstein,! consider
that two years are necessary to produce the complete
evolution of the elm-feeding PempJiigince. The last
author, in conjunction with M. Courchet, has experi-
mented with insects confined under glass cylinders
containing grasses growing in moist earth. Up to the
present time I believe they have failed to prove their
descent to the roots and hibernation thereon. No
doubt the artificial conditions rendered necessary by
the experiment must present difficulties, but neverthe-
less more proof is required before this subterranean
habit, connected with assimilation of such diverse food,
can be accepted as more than an hypothesis.

It by no means appears that all Pemphigince require
two years for their complete cycle of life. The egg of
some species is certainly consigned to the bark of
the tree infested, where its vitality has been proved
to resist very low temperatures. The warmth of
returning spring is only required to bring the young
into active life. It is remarkable, however, that the
cold of late December will often find the winged
females still vigorous, and delivering themselves of the
true sexes under the protecting bark.

This oviposition under the bark has been confirmed
by the researches of Messrs. Riley and Monell, who,
moreover, think it improbable that any of the species
so entirely change their habit as suddenly to feed on
such dissimilar food, and to become earth-inhabiters
during the winter. §

In expressing my own hesitation to accept M. Lich-
tenstein's hypothesis, I will acknowledge that the com-
parative scarcity of species of these Pemphigince in
Britain has prevented me from studying them with

* Koch, ' Du Pflanz. Apbiden.,' p. 293.
t Derbes, ' Ann. des Science,' 1. c.

i Vide Licbteustein, ' Bull. Soc. Ent. de Fr.' (6), iv, 241—24.2.
§ Riley and Monell, ' Notes on tlie Apliididse of the U. S. of America,'
Washington, 1879,

122 BRITISH APHIDES.

the same assiduity as he has clone. In many parti-
culars he can speak with more authority on a group
which he has made his speciality.

o..

Pemphigus spirothece, Kocli. Plate CXI, figs. 8 — 9 ;
and Plate CXII, figs. 1—6.

Fenq^higus affinis, Koch.
Pemphigus sjpirothecce, Pass;
. Puceron de peupUer, Reaumur.*

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-060xO-030 l-52xO-76.

Length of antenna 0-030 0-76.

Elliptical, wholly pale green or yellowish ; very
lanuginous. Antennse short, formed of four joints only ;
but a constriction of the third joint shows a tendency
to develop another joint. Eyes very small; rostrum
reaches to the second coxes. The abdomen and legs
clothed with cotton-like tufts.

]} I have never met with the winged form of P. spiro-
thecce, but Koch figures it apparently under the name
P. affinis ; and Passerini describes it as being very like
the imago of P. hursarius. The fourth wing-nerve
rises from a point scarcely beyond the half length of
the stigma. The former species may be distinguished
from the latter by the abundance of woolly matter
which clothes the apterous form of P. spirothecce.

The covered dwelling of this species is formed by
the Queen Aphis, by puncturing one side of the leaf-
stalk of the poplar, most usually that of Populus nigra.
This irritation causes the stalk to flatten and, curve
itself into an elastic spiral, the edges of which press
ao-ainst each other, so as to form a chamber, in which
the species multiplies and undergoes pupation.

* ' Mem. des Insectes,' t. iii, pi. 28, figs. 1 — 4.

PEMPHIGUS SPIROTHEOJ;. 123

The more normal forms are represented by the
figures 1,2, and 3, Plate CXII ; but in the previous
plate a gall is depicted which departs much from
the usual shape. The insects taken from it, however,
so well accord with Koch's and Passerini's description
of P. sjrirothecce, that I conclude the structure to be
the work of that species.

I have compared the British insects also with those
sent to me from the South of France, with which they
well agree.

M. Lichten stein found these coils still tenanted by
wino-ed females in December. He informs me that he
kept some of these in confinement at Cannes during
the winter of 1878, and that from them he bred non-
rostrated males and females. In another letter he
informed me that he had secured an egg from which in
the May following he hatched a female. He placed
her on a suitable tree in his garden and almost in;-
mediately she commenced her operations for con-
structing a gall, or its representative. Here she bred
her young, and later in the year these assumed wings.

Through the kindness of this naturalist I am en-
abled to figure the oviparous female with her included
egg, and likewise the diminutive male. Both of these
are mouthless. The antennae of the former are very
simple in structure, and consist of only four articula-
tions. The latter insect shows the recurved male organ.
The sizes of these sexes are, for the former, 0*02 inch,
0-5 mm., for the latter, 0-013 inch, 0*3 mm. They
were captured in December.

Dr. P. Low, of Vienna, also experimented Avith these
AphideS; and confirmed the observation that the produce
of the winged female is mouthless, and that both sexes
eventually descend into the ground for hibernation;
a circumstance quite in accordance with Passerini*s
supposition that such might prove to be their habit.
The egg probably is consigned to a crevice in the
bark of the Poplar, from which the foundress of the
new colony emerges in the spring.

VOL. III. ^

124 BRITISH APHIDES.

Reaumur gives a spirited woodcut of a coiled gall
on the poplar ; and one cannot doubt that it was the
work of Pemijliigus spirothecce.

Koch's description of the distorted leaf-stalks as
" Stopselzieherartig gewindene Beulen " (corkscrew-
twisted bladders), clearly identifies his P. affinis with
Passerini's P. spirotlieccB. The diagnosis of the
insects also well suits both. Koch says the fourth
antennal joint is much shorter than the two following,
and that whilst the species is intimately allied with
P. [hursmmis, it is nevertheless smaller and woolly.
P. affinis of Kaltenbach is a large insect, and, as Pas-
serini remarks, is not identical with Koch's P. affinis.
Except that the last specific name is preoccupied,
priority should be given to that of Koch, who first
clearly described the insect.

Koch's figure represents the insect covered with long
hair instead of flocks of cotton ; a defect likely to
mislead the searcher.

This species has not been, hitherto, recorded as
British. Probably it is nowhere plentiful in this
country.

Pemphigus laotucaeius, Pass. Plate OXII, figs. 7 — 13.
Amycla fiiscicornis, Koch.

Apterous viviparous female.

Incli. Millimetres.

Size of body 0-080 X 0'045 2-02 X 1-13.

Length of antennae 0*020 0*50.

Oval, pale yellow, mealy, with an abundance of long,
waxy, silk-like fibres, which proceed more particularly
from the anal rings. Early in the year these insects
are quite blind, but in the autumn they show obvious
eyes, though very small. Antennae short and fuscous
towards the tips. Tail and nectaries none. Antenna,
legs, and a squarish spot on the occiput sooty grey.

PEMPHIGUS LACTUOARIUS. 125

Abdomen pale, with two rows of minute lateral dots.
Rostrum reaches to the second coxje. The antenna!
joints vary in number according to the size of the
individual.

The young which are born in the early year are
linear and nearly cylindrical. They have much the
appearance of young centipedes, which are pretty con-
stant companions of this and other underground
species of Aphis. These young have only four antennal
joints, which increase to five, not counting the nail, as
they pass into more mature forms. Except that these
young show a short rostrum, they might be taken for
miniature Juli.

Koch saw these a,bnormal forms born, the adults
having been placed by him between watch-glasses.
Like this naturalist, I have not met with the imago.
Nevertheless, I have no doubt that my insect is iden-
tical with P. lactucarius of Passerini. The diagnosis,
habitat, and food well agree. The last author describes
the winged female as a true PempMgian, and also states
that the pupa is lanuginose.

This insect is plentiful in some light and sandy
soils, which they excavate in the vicinity of the roots
of various plants, such as Lactuca sativa, L. virosa,
Sonchus oleraceus. The Aphis is very plentiful at
Haslemere, where I found them at the roots of the
wall-flower {Glieiranthus Cheiri), the fetid chamomile
{Anthemis cotula), and the goose-foot {Ghenopodium
alhmn). But they are most common at the decaying
roots of the garden lettuce, few of which, in January
and February, can be uprooted without showing their
downy flocks.

The communities inhabiting these earth cavities are
not large. They do not usually number more than
eisfht or a dozen individuals, which become darker in
colour after exposure to the air. This they seem to
shun, for they speedily re-bury themselves after being
unearthed.

Towards the middle of September, after the corn

126 BRITISH APHIDES.

had been cut some weeks, I found P. laducarms very
abundant at the roots of the wheat stubble. These
apterous insects were full of embryos, ready for extru-
sion. Although Persicaria and other weeds were in the
neighbourhood, the roots of which I carefully searched,
I could find no Aphides of other species. Siphono-
pliora granaria is such a common corn pest that I
thought some underground form might possibly pre-
sent itself, to explain the total disappearance of the
insect at the gathering in of the crops. However,
nothing discovered led me to believe in such an under-
ground habit of ^S'. granaria. The different winged
forms of course precluded all likelihood of any con-
nection between this Aphis infesting the ear and the
Pemphigus nesting at the root of the wheat.

Specimens of these last were kept in moist earth
under a bell glass for many days, but I failed in pro-
curing either images or pupa3 from them.

The large females are well suited for showing the
fine net-work of tracheae which ramifies throug^hout
the body. These air-tubes may be readily separated
by teasing with fine needles, after the insect has been
placed in syrup or a weak solution of salt, to prevent
the breaking-up of the delicate tissues.

It is not easy to see why Koch separated this and the
preceding P. fuscifrons from the genus Pemphigus,
His genus Ami/cla seems to depend on characters too
indefinite and variable to allow of certainty. He seems
to rely chiefly on slight variations of length in the
antennee and rostra in the three species he describes
in his genus.

PEMPHIGUS PALLIDUS. 127

Pemphigus pallidus, Haliday. Plate CXIII, figs. 1 — 5.

Eriosoma imllida, Haliday : Curtis.*
Pemjpliigus albusj Liclit.
„ tilini, Liclit. ?

Apterous viviparous female. Queen Aphis.

Inch. Millimetres.

Size of body O-llOXO-070 2-79xl-77.

Length of antennge 0'025 0*62.

Large, oval, white or pale yellow, which by age turns
browner. Antennae five-jointed. Eyes very small,
almost obsolete. Legs and antennae rather fuscous.
Hind legs much longer than the other four. The
members of the first brood are much smaller than the
insects which issue from the Qgg ; they are of a ferru-
ginous pale yellow.

Pupa.

Long-oval, yellow, with pale wing-covers. Eyes
red. Abdomen greyish.

Incli.

Size 0-070 X 0-035.
Winged viviparoufi female.

Inch. Millimetres.

Expanse of wings 0-220 5-58.

Size of body O'OSO X 0-035 2-02 X 0-88.

Length of antennae 0*020 0'50.

Variable in size. Head and thorax bluish-black.
Abdomen oval, yellowish, with fine lateral dots. Eyes
red. Legs and antennae fuscous. Wings moderately
long. Veining fine and pale brown. Stigma greenish.
The hind wings, like other Pemphigince, have two
oblique veins. Notwithstanding the similar woody
character of the two galls, both of which are formed
without foot-stalks on the midrib of the leaf of the
elm, the above-described insect probably is not that
called by Ratzeburg Tetraneura alba, which seems also

* Curtis, App. 279.

128 BRITISH APHIDES.

to be that of Kessler and Low. That genus necessi-
tates the presence of one single obhque vein in the
lower wing. All the specimens I possess show two
oblique veins, which I look upon as constant.

M. Derbes, in 1868, described an insect which feeds
on Pistacio terehinthmn^ to which he gave the name
PemjyJiigus pallidus, but this manifestly is quite a
different species from this on the elm tree.*

As Haliday publislied his researches in 1839, priority
should be given to the name he gave his insect, and
accordingly I retain it,

Haliday's description of Eriosoma iDallida is as
follows : — " It inhabits the mountain-elm. Its follicles
are more solid and embedded in the leaves, near the
base of the midrib, not elevated on a foot-stalk, ....
than in Eriosoma ulmi gallarimi. The apterous female
of E. ijallida is white. The follicles burst about the
beginning of August. ■ The society then is very
numerous, and the farinose secretion more abundant
than in that species." He then describes the winged
form and says, "the nerves of the upper wingare nearly
as in E. ulmi gaUarum [Tetraneuraulmi), but the lower
have two nervures (in the place of one) springing
from the sub-costal. The joints of the antennae also
are of different proportion, the sixth being rather
longer than the fifth. "t

Pemphigus filagints, Fonsc, Pass. Plate CXIV, figs.

1—4.

Aphis filaginis, Boyer de Fonsc.
Pemjpliigus gnaphalii^ Kalt., AYalk., Hardy.

Apterous viviparous female.

Inch. Millimetres.

Size 0-080X0-050 2-02xl-27.

* M. Liditenstein proposes, in a letter to me, that, to avoid confusion,
this insect should in future be called Pemphigiis Derbesi.
t A. H. Haliday, ' Ann. Nat. Hist.,' vol. ii, p. 189.

PEMPHIGUS FILAGINIS. 129

Oval, pale j^ellowish-green or dark grey, thickly
covered with a white powder. Antennae and eyes
black. Legs yellow and moderately long. Tarsi and
tips of tibias black. Rostrum reaches to the second
coxa).

Winged viviparous female.

Inch. Millimetres.

Expanse of wings 0*230 5'84.

Size of body 0-080 X 0-030 2-02x0-76.

Length of antennaB 0-020 0'50.

Head, thorax, and eyes dark brown or black.
Third antennal joint slightly imbricated, Abdomen
oval, yellowish-green or orange, powdered. Legs
rather short and darkish yellow. Wings with mem-
branes rather fuscous yellow. Insertions yellow.
Stigma transparent, pale green, with a darker internal
spot. Veins green and ver^^ fine. Stigmatic vein
curved. Eostrum reaches to the second cox^e.

Oviparous female.

Oblong, dull yellow. Eyes very small. Antennae
short and simple, the joints restricted to four. Legs
very short. This sex is mouthless, the sucking organ
being represented by two buccal plates.

Found hiding under the woolly flower-bunches of
the cudweed Gnaphalium germanicum. The apterous
forms some years ago were taken by Mr. J. Hardy as
far north as Scotland. The insect seems to be more
plentiful in France than in England.

Li concluding this description of the British Pem-
phigince, I believe M. Lichteustein will allow me to
add a short extract from a letter he addressed to me
in 1877 : as he has since in public expressed his
views, I may be permitted to quote his words.

*' The fact on which I claim the attention of my
Entomological colleagues is, that the underground
Pemphigince (P. Boyeri, P. ca^rulescens) lay pup^e,

130 BEITISH APHIDES.

giving sexuated forms, whilst the aerial PemphigincB
(P. bursarius, P. affinis, &c.) lay what I have called
" oeufs bourgeons," giving agamous insects with rostra,
and having to change their skins four times before
laying eggs (oeufs bourgeons?). This leads me to
believe that the underground insects are only a form
of the aerial ones, and the principal as being the
sexuated."

Again, in a communication more recently made to
the Academy of Science of Montpellier, he details some
experiments made to prove the identity of Pemjpliigus
jilaginis with Pemphigus bursarius. Experimentally
he bred " thousands " of the former under a bell
glass containing a living plant of Gnaphalium pre-
sumably free from P. filaginis, on which he purposely
had placed specimens of P. bursarius. Subsequently,
he has expressed his intention to hatch some eggs of
P. filaginis, — which are exceedingly plentiful at Mont-
pellier, to see if they will produce the "fundatrice" of
P. bursarius. This experiment is the more necessary
since it is exceedingly difficult to eliminate all germs of
P.filaginis from such a woolly plant as Gnaphalium.

Shortly expressed, M. Lichtenstein thinks it probable
at least, that the aerial Pemjjhigince are dimorphic like
Phylloxera. That the winged forms produce two kinds
of agamous insects, one of which undergoes several
moultings, and then produces the ordinary aerial males
and females : the other agamous insect descends into
the ground, and, after taking some such form as Pe^n-
phigus Boyeriy produces " pupse '^ which do not moult.
These finally give birth to the mouthless but other-
wise perfect sexes as above.

Proofs are yet wanting, but Entomologists have
much to hope from the perseverence and industry of
M. Lichtenstein.

TETRANEUEA ULMI. 181

Genus XXYII.— TETRANEUEA,* Hartig.
Gallenlatts.

Rostrum in the adults very short.

Antennas short, about equal to the head and thorax ;
six-jointed, the last joint ending with the usual button ;
the third joint much ringed.

Cornicles and tail entirely wanting.

Wings similar to those of PempJiigus, except that
there is only one oblique vein in the hinder wing.

The stigma has a dark included spot.

Legs short, as in Pemphigus.

These insects live in small pedunculated pseudo-
galls, which are usually constructed from the midrib
of the Elm leaf. The mature insects perforate the side
of the gall, which expands into a more or less irre-
gular hole from which they find an exit.

There is but one British species belonging to this
genus as yet recorded. M. Lichtenstein, however, sent
me deep-red, hairy galls from the leaves of the Elm,
which differed much from those made by the English
insect. He jDroposes to call the French insects Tetra-
neura rubra. Tetraneura alba also is a Continental
species, which has not been observed in England.

Tetraneura ulmi, Dp, Geer. Plate CXIY, figs. 5 — 13.

ApJiis gallarum uhni, De Geer, Geoff., Yon Gleichen.
Tetraneura ulmi, Hartig, Kalt., Koch., Pass.

Apterous viviparous female. Queen Aphis.

Incli. Millimetres.

Size of body 0-085X0-055 2-14xl-39.

Length of antennee 0'012 0"30.

* From rerpa {pro rirapa), four, and vtvpov, a nei've.

132 BRITISH APHIDES.

When full-grown; globular, very sliiniug dark green,
or nearly black after removal from the gall and expo-
sure to the air. Antennae very short and only four-
jointed. Body furnished with a few fine hairs, lout not
clothed with any abundance of cottony fibre. Eyes
small and black. Legs short.

Notwithstanding some risk of recapitulation (since
the life-history of Tetraneura has much in common
with that of Pemphigus), I append my own observa-
tions on this species, which accord with those of Dr.
H. Kessler, of Cassel, and the American naturahsts.

Early in the spring, minute, longish, black, shining,
un winged insects may be found close to the leaf-buds
of onr elms. They are about O'OIO of a milhmetre
long. These are the Queens of the colonies which are
to appear through the year.

As soon as the young leaves unfold, these insects
commence their irritating actiou, and the leaves then
show, by the red spots on their under sides, that there
is a diversion of the sap, causing a cupping of the
edges of the rising blister, which finally arches over
and encloses the growing Aphis.

So far as my observations go, the leaf is attacked
not only at the midrib, but also in the spaces between
the other leaf-veins. In all cases, however, the gall
becomes pedunculated, and rises a considerable dis-
tance above the surface.

The size of these galls would seem very much to
depend on the season and the luxuriance of growth of
the trees. German specimens* are described as either
round or of an oval form, the long diameter being
about one centimetre ; but I have certainly in England
seen them larger than three eighths of an inch.

In the neighbourhood of Cassel they are described
as studding the trees occasionally in such masses, that
they bow down the points of the branches.

* For more minute particulars the reader is referred to Dr. Kessler's
'Die Lebeusgescliiclite der auf Ulmus campestris vorkommeuden
Apbiden-Arten,' &c., and M. L. Ooui'cliet's ' Etude sur les Galles pro-
duits par les Aphidiens/ 1879,

TETEANEURA ULML 133

"What takes place within these closed chambers can
only be surmised ; but from the cell- walls the solitary
Aphis gets her nourishment, and within them she
undergoes four moults (Riley and Kessler). After
these have been completed, she commences reproduc-
tion. The young vary much in number, but are all
blackish, with paler undersides ; their hinder parts
are furnished with a white woolly coat, mostly pro-
ceeding from the last body-rings. After the first
moult they become greener.

Throughout the summer of 1879 this species was
common on most of the elms at Old Romney in Kent.
They seemed, however, mostly to affect the leaves of
Ulrims suberosa.

The galls, when slit open early in June, showed
that they were still tenanted only by the Queen Aphis,
who had not completed her moults, for no exuvise could
be found. At this time the same trees were tenanted
by the leaf-rolling Schizoneura ulmi, which were much
more advanced, and were commencing to migrate.

The progeny of the second generation numbers
forty or more, and after a while gives rise to the pup^e,
which again in due time disclose the winged females,
just as in Pem^jhigns. These imagos issue from the
pseudo-galls at different intervals, but the population
of the gall is kept up pretty constantly throughout
the summer by the Queen Aphis.

Winged vivijjaroiis female.

Inch. Millimetres,

Expanse of wings 0*240 6*09.

Size of body 0-080 X 0-030 2-02 x 076.

Length of antennae 0'025 062.

Head and thorax black and naked. Abdomen long-
oval, dark green or olive. Slightly powdered. An-
tenna very short ; third and fifth joints ringed.
Nectaries and tail wanting. Wing-membranes smoky.

134 BRITISH APHIDES.

Cubitus, stigma, and wing-veins broMaiisTi. Hind
wing witli a single oblique vein.*

Oviparous female.
Size . . . 0-027 X 0-020 mm.

Very small, globular. AntennsD only partially deve-
loped, and composed of four joints. Rostrum none.
Eyes minute, and sliowing but seven or eight facets.
Legs short. The abdomen is occupied almost exclu-
sively by one large egg ; indeed, this insect may be
regarded as httle more than a walking seed, which is
capable of choosing its own place for deposit.

The first winged forms issue from the galls about
the last week in June. One of these, captured whilst
flying, appeared like a small fleck of white down. It
was placed under a watch-glass for after examination ;
but during the night she produced upwards of thirty
young ones, all of which possessed remarkably long
rostra, which trailed behind them whilst walking.
One of these insects is represented in Plate CXIV,
fig 10.

On cutting open a pedunculated gall, on June the
11th, the single Aphis was turned out. She was pale
green, with a brown head, legs, and eyes. Two
moulted skins were found at the end of the gall,
together with an abundance of woolly matter. This
Queen-mother was perpetually engaged in wriggling
from side to side, and pricking the inside of the gall
with her rostrum.

The leaves viewed from the underside show oblong
orifices or slits at the junction of the peduncle. These
ventilating slits are partially closed by a dense fringe
of jointed threads, which doubtless prevents the
entrance of many a prying parasite. The cells were
full of winged insects on the 20th of July.

* I have captured winged females liaving not more than one third of
the above measurements . Probably these vs'ere of the second series,
which occurs in autumn.

TOXOPTERA. 135

Although, the galls in EDglancl take several forms, I
am not disposed to multiply species on this account.

Some structures have two peduncles, some have two
orifices, some spring from the midrib, whilst others
rise from the green fleshy portion of the leaf. All
these show a purple colouring at their apices.

The genus Toxoptera was formed by Koch to receive
some insects which are somewhat anomalous, inasmuch
as they combine the characters of Mijzus and, as far as
the wing-veining goes, of Pem])higiis.

Two species are known of this genus, viz. Toxoi^tera
aurantice, Koch, and T.graminum, Eondani. The former
is common on the Orange, the Citron, and the Camelia
in Germany, South France, and Italy ; but, as these
trees are exotics here, this Aphis cannot be regarded
as indigenous to Great Britain. Toxoptera graminum,
during the summer, is an inhabitant of various Grasses,
affecting the lower leaves, and numerously so.
Triticum, Hordeum, Avena, Sorghum, and Zea are
habitats of this species.

The characters of Toxoptera are : Antenna seven-
jointed, and placed on small remote frontal tubercles.
Cornicles and tail moderately long. Wings with the
cubital vein but once-forked. The rest of the characters
as in Myzus.

Rondani says that in the year 1852 the streets of
Bologna were swarming with innumerable troops
(" turmis innumeris ") of T. graminum to the annoy-
ance of the inhabitants. " Urbis nostrse vias cadavera
hujus formjB primo mane velabant."* I suppose a
little exaggeration may be allowed to an enthusiast.

Sir Joseph Hooker kindly made several searches for
this Aphis in the orangery of the Royal Botanical
Gardens at Kew, and Sir Charles Isham also made
examinations of the plants in his fine camelia house at
Lamport Hall.

In both cases the search was ineffectual.

* Rondani ' Ann. delle Scien. Nat. de Bologna.'

136 BRITISH APHIDES.

Altliougli no species as yet has been recorded
British, a passing notice of the genus is desirable, and
may lead to its discovery amongst our G-ramine£e.

Similar remarks will in a measure also apply to
Passerini's genus Aplonetjea. The single species
'known^Ajjloneura lentisci, inliahits follicles constructed
on the leaves of Pistacio lentiscus. The chief character
advanced for this genus seems to be the horizontal
position assumed by the wings, when at rest. This
insect is not known in Great Britain.

LIST OF AUTHORS

WITH THE

APPROXIMATE DATE OF THEIR MEMOIRS ON

APHIDES.

Lewenhoek, a. von. Arcana Naturse. 1690.
»^Reaumuk. Mem. des Insectes. 1737. ru^ ,y i^^

GrEOFFROY. 1740.

Trembley, A. Mem. sur les Polypes. 1744.
. LiNN^us, C. Fauna Suecica ; Sys. Nat. 1761. ^-^^ ^'^-
ScopoLi. 1763.

SuLTZER. Hist, des Insectes. 1766.
i-^GLEioHEN, VON. Ycrsucli ciner Geschichte der Blatt-

lause. 1770.
v^De G-eer. L'Histoire des Insectes. 1778.
Bonnet, Ohas. CEuvres d'Histoire Naturelle. 1779.
Fabricius, J. C. Ent. Syst., tom. iv. 1794.
ScHRANK, Fr. VON. Fauna boica. 1801. ^-'' '^ ■
i^Kyber, J. F. Ueber die Blattlause ; Germars Mag., i.
1815.
DuvAU. Aphis fabas. 1825. \^

Hausmann, Fr. Illigers Magazin, Bd. i. 1801.
DuTROOHET. Ann. Sc. Nat. 1835. ^

^ BuRMEiSTER, H. Handbuch der Ent. 1835^.
MoRREN, Chas. Ann. des Sc. ; Puceron du pecher.
1836.
u^ZetterstedTj J. W. Faun. Lapp., fasc. ii. 1838.
Siebold, von. Ueber die vivip. Blattlause. 1839.
^ Hartig, J. Germars Zeitschrift fiir Ent., iii. 1841.
V Fonscolombe, Boyer de. Ann. Soc. Ent. de France.
1841.
Steenstrup. Alternation of Generations, 1842.

138 LIST OF AUTHOES, ETO.

^-^ALTENBACH. Mon. der Pflanzenlause. 1843.
^'Eatzeburg. Die Forst-Insecten. 1844.

DuFOUR, Leon. Recherclie sur les Hemipteres.
u-Heyden, VON. Museum Senkenbergianum, Heft. 11. /H

Amyot. Ann. See. Ent. de France, 2 ser., t. v, 1847.
- Haliday. Ann. Nat. Hist. 1839.

Newpoet. Linn. Trans., vol. xx, p. 281. 1846.
Walker, F. Ann. of I^at. Hist. 1848.
MosELEY, Sir 0. Gardeners' Chronicle, vol. i. 1841.
Owen. Lectures on Invertebrata. 1843, 1851.
x^FiTCH, Asa. First Kep. on Noxious Insects. New

York. 185l^f
v-HuxLEY, Thos. Reproduction of Aphis, Linn. Trans.,
xxii. 1857.
TouGARD. Ann. Soc. Hort. de Paris.
. Koch, C. L. Die Pflanzenliiuse. 1857. ^^i'^-''^*'7.
Leuokardt. Zur Kenntniss des Generationswechsels.

1858.
Thomson, Allen. Article " Ovum," Todd's Cyc. of
Anat. 1859.
" Passerini, G. GliAfidi. 1860._
•-' Balbl\ni. Compt. rendus, t. Ixii. 1866.

Mecznikow. On Homoptera. ]866.
-' SiGNORET. ^Comp. rend., p. 1259. 1867.
ScHiODTE. ';Jidsskrift, 3 ser., vol. vi. 1869.
Curtis, W. Linn. Trans., vol. vi. 1802.
Curtis, J. B. British Entomology and Journal of

Roy. Agric. Soc, vol. vii, &c. 1846.
Derbes. Ann. des Sci. Natur. 1869.
^ Riley, Chas. Reports on Noxious Insects. 187$ —
1879.
Low. Ueber eine dem Mais-schadliche. 1877.
Kessler, H. F. Lebensgeschichte der Aphiden-Arten.

1878.
Lichtenstein. On Phylloxera, &c. 1876 — 1879.
Thomas, C. Eighth Report on Noxious Insects of
Illinois. 1879.
y Monell, J., and Riley. Notes on Aphididse. 1879.
CouROHET, L. Etude des Galles. 1879.

INDEX TO VOL. III.

PAGE

PAGE

American blight, first appear-

Banks, Sir Joseph, on Ame-

ance of, in England

91

rican blight

91

Amycla fuscifrous 113, 115,

126

Birth, rate of, in Aphis

99

— fuscicoi-nis .

124

Blind Aphides, remarks on

Auocecia corni .

107

7, 68, 88

,124

Ants' nests tenanted by Aphi-

Boussinganlt, remarkable in-

des

69

stance of quantity of

Aphidida3 found with Cica-

boney dew from a single

did93 in the Purbeck beds

3

lime tree .

. 36

Aphioides bursaria

117

Aphis alni

31

Callipterus, general charac-

— antennata .

14

ters of

12

— betulse

14

— alni .

. 31

— betulicola .

15

— betularius .

. 14

— bursaria, Kirby and Spence

117

— betulse

. 15

— coryli

17

— betulsecolens

. 17

— f agi ....

37

— betulella

17

— foliorum

97

— betulicola .

. 15

— gallarum ulmi

131

— carpini

. 19

■ — juglandicola

32

— castanege

. 26

— juglandis

40

— coryli

. 17

— lanigera

89

— juglandicola

. 32

— longipes

59

— juglandis

. 40

— longirostris .

62

— querceus

. 24

— nnda pini

50

— quercus

. 21

— p"^ce8e

58

— quercus, probably identica

I

— pini ....

50

witb Yacuna dryophila o

F

— pinicola

52

Huxley

23

— quercus, Linn.

62

Camera drawing, remarks on

i

— radicum

68

Chestnut Gaylouse of Fitch

28

— roboris . . 69, 71

Cinara roboris ,

71

— salicis

53

Classification, introductory

— saligna

54

remarks on

1

— tilise ....

34

Coleoptera in Carboniferous

— trenmlse

81

beds

3

— tuberculata .

14

Courchet on Aphis galls

83

— viminalis

53

Curtis, William, on willow

Aploneura lentisci

136

Aphis . •>

10

55

140

INDEX TO VOL. III.

P^GE

Degradation in Apliis . 7

Derbes on Pemphiginse . 121

Devonian indications of in-
sects . * .2
Diptera in Solenliofen roofing

stone . . .4

Dorsal gland in Laclinus

viminalis . . .56

Distribution of A.pliides . 2

Dry apliis . . .71

Dryobius, general cbaracters

of . . . .70

— Croaticus . . .74

— roboris . . .71

— migrations of . .77

Endeis rosea and E. bella
Ephemera, primaeval forms of
Eriosoma of Leach

— lanigera

— mali .

— pallida

— populi
Exhausting action of lime

Aphis . ,

116
3

81

89

89

127

117

36

Galls made by Schizoneura . 81

— by Pemphigus . 86, 120

— by Tetraneura . .134
Gerstacker's estimate of num-
ber of known recent in-
sects . . .4

Globules in Aphis galls, feecal

matter . . . 100

Goss, Herbert, on the anti-
quity of insects . . 4

Hair, rapid growth of, in

Aphis . _ . .99

Haeckel on origin of insects . 5

Hemiptera found in Permian

rocks . . .3

Huxley on anatomy of Aphis

and Vaccuna . . 23

Imagination in Science

Kant's remarks on geological

testimony . . .2

Kessler on Pemphiginae . 83

PAGE

Lachninse, general characters

of . . . 30,42

Lachnus agilis . . 47

— cupressi . . .46

— dentatus . . .57

— fagi . . . . 37

— fasciatus . . 71, 73

— grossus . . .58

— hyalinus . . .48

— juglandicola . . 32

— juglandis . . .40

— juniperi . . .44

— longipes . . .59

— longistigma . . 61

— macrocephalus . . 48

— picese . * .58

— pini . . . .50

— pinicolus - . .52

— quercus, Kalt. . . 62

— roboris . . .71

— viminalis . . .53
Lepidoptera in Solenhofen

stones . . .4

Liassic beds, remains of in-
sects in . . .3
Lichtenstein, experiments on

Pemphiginse . . 121

— nomenclature of Aphides . 83
Life history and cycle of

Pemphiginse . .112

List of Memoirs on Aphis . 137
Low, Dr. Franz, on Aphides of

maize . . .116

Lubbock, Sir John, on deve-
lopmental and metamor-
morphic changes . 6

— on Campodea as represent-

ing a primaeval type . 7

Males, supplementary and

dimorphic . . 20, 35, 39

Manna, dei apicollori (note) . 43
McLachlan on Aphis galls . 105
Modes of checking Aphis

ravages . . .94

Migrations of Aphides 66, 86, 103
Mimaphidus ulmi . . 104

Mouth organs, on develop-
ment of . . .7
Mouthless sexes 84, 93, 102, 113
Mlillei', Fritz, on parent stock

of Insecta . . 5

Myina flava parasitic on

Aphides . . .18

INDEX TO VOL. III.

141

Myzocallis quercea

— quercus

— coryli
Myzoxylus mali

PAGE

, 24
. 21
. 17

. 89

Nomenclature according to

Lichtenstein . , 83

Oleo Sancti Jobannis a vul-

nearium . . .107

Oolitic beds, insect remains in 3

Orthoptera, primaeval forms

of . . . .3

Ova of Dryobius, large masses

of . . . 73, 76

Ovum not to be confused witli
embryo, pupa, &c. . . 87

Palseontina oolitica . . 3
Paracletus cimiciformis . 67
Parallelisms between Pem-
phigus and Phylloxera . 82
Parent stock of Insecta, theo-
ries on . . .5
Pemphiginse, general remarks

on . . . . 112

Pemphigus affinis . . 122

— Boyeri . . . 113

— bursarius . . .117

— filaginis . . . 128

— fuscifrons . . . 113

— gnaphalii . . . 128

— lactucarius . . . 124

— pallidus . . .127

— pyriformis . . .119

— spirothecse , . . 122

— vagabundus . . 109

— zese maidis . . . 113
Phyllaphis fagi . . 87
Polygamy in Aphides . 74
Pterocallis, characters of . 31

— alni . . . .31

— juglandicola . . 32

— tilise . . .34
Pterochlorus longi^Des . 59
Ptychodes juglandis . . 40
Puceron de Chene . . 62

— detilleul . . .36

— de peuplier . . . 122
Purbeck limestone beds, Ho-

moptera in . .3

Queen Aphis, use of the term 89

PAGE

Reaumur on poplar Aphides , 119
Red stains from Aphides

44, 55, 59
Riley and Monell on Aphis

galls . . . .121

Rhizobiinse, remarks on . 65

Rhizobius helianthemi . 68

Schizoneura Americana

91, 97, 103
. 107

— corni

— fodiens

— f uliginosa .

— lanigera

— lanuginosa .

— Reaumuri synonymous

with puceron de tilleul .

— ulmi . . . .

96,

94

96

89

104

36

97
107
107
88
81
86
95
80

Segmentation

— venusta

— blind larvse of

— life history of

— migrations of

— subterranean habits of
Schizoneurinse, characters of

in Insecta and
Crustacea . . 6

Sequence, geological, in insect

orders . . . 4

Sipha maidis, Pass. . . 116

Spread of American blight . 91
Stomaphis quercus . . 62

— Tugall's notice of . .63

— Linnasus on . . ,64
Stonesfield beds, insects in . 3
Sudden appearance and dis-
appearance of Aphides

57, 58
Sugar, the manufacture of,
suggested from honey
dew . . .55

Supplementary males . 20, 39

Synopsis of genera of British

Aphididae . . .11

Tendency to suppression of

wing veins . . 42

Tetraneura, general charac-
ters of . . . 131

— ulmi . . . 131
Thysanura, fossil remains of . 4
Toxoptera aurantiae . .135

— graminum . . . 135

142

INDKX TO VOL. III.

PAGE

Trama, general characters of. 68

— flavescens .

. 68

— pubescens .

. 68

— radicis

. 68

— troglodytes .

. 68

Tjchsea setasia

. 116

PAGE

Vacuna dryophila, Huxley,
probably identical with
Callipterus quercus . 23

Yai'iation in wing veining . 92

Xenoneura antiquorum . 3

Eeeatum. — Page 6, line 28, for apterous read apodous.

PRINTED BY J. t. ADLARD, BARTHOLOMEW CLOSE.

PLATE LXXXVII.

Callipterus BETULA.RIUS. (Page 14.)

Fig. 1. — Apterous viviparous female. The abdo-
minal tubercles are tufted with capitate hairs.

Fig. 2. — Apterous oviparous female. The last three
abdominal rings are dilated from the presence of an
egg ready for extrusion.

Fig. 3. — "Winged female, showing the great length
of the antennse.

Fig. 4. — Head of the last insect, showing the stem-
mata and the two basal joints of the antennse.

Fig. 5. — Trumpet-shaped cornicle of Fig. 2, with
enlarged view of the capitate hairs, the summits of
which have each a cavity similar to that shown in
Plate XXII bis. These hairs probably are tactile
organs.

Fig. 6. — Caudal appendage of Fig. 3.

Fiof. 7. — Last three articulations of the antennaB of
Fig. 3. The setaceous seventh jomt is obvious.

^LATE LXXXVir.

/■■

CoLil

ucfefon dfl, ,1 Hfi^

ipterus beUila...,^.

PLATE LXXXVIII.

Callipterus betulicola. (Page 15.)

Fig. 1. — Winged viviparous female. The body,
antennae, and legs are irregularly tufted with cotton-
like matter. The length and delicacy of the wings
may be noted.

Fig. 2. — Profile view of the apterous viviparous
female.

Fig. 3. — Part of the antenna of Fig. 1.

Callipteeus coryli. (Page 17.)

Fig. 4. — Apterous viviparous female.

Fig. 5. — Winged female. The wings are folded
pent-wise, as is usual in Aphis when the insect is at
rest.

Fig. 6. — Head and antennae of the last insect.

Eig. 7. — Anal valves and nectaries of winged female.
Similar appendages are visible, more or less markedly
in all the species of this genus.

PLATE I.XXXVILI

Callipter-as betui:coifcL 1-3.
V CoT'ylx 4— 7 .

' B-BmJ<ton, (Je2 ei- tit.

WesI Hnvnraii i. ('

PLATE LXXXIX.

Callipterus cAEPiNi. (Page 19.)

Fig. 1. — The pupa.

Fig. 2. — Winged viviparous female evolved from
Fig. 1.

Fig. 3. — Apterous oviparous female. The caudal
rings are developed somewhat into the form of an
ovipositor.

Fig. 4. — Apterous male, drawn of relative size to
the last. Several examples were taken in company
with Fig. 3.

Fig. 5. — Winged male. All specimens I have seen
show a curved post-costal nervure, and they want the
cloudy stains in the upper wings.

Fig. 6. — Head and antenna of winged male. This
sex is rostrated.

Fig. 7. — Part of head and antenna of oviparous
female.

Fig. 8. — Cornicle and caudal region of the pupa.

PLATE LXXXIX.

Ca.lliptei'us caa?pirLi..

G.B -Bucfcton, it)., cb Uth..

West Ntwiiuin i- 0° mf:-

PLATE XC.

Callipterus quercus. (Page 21.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Pupa of the same.

Fig. 3. — Oviparous female.

Fig. 4. — Profile view of the winged viviparous
female, showing the six dorsal papillae and the short
rostrum characteristic of the genus.

Fig. 5. — Winged male. The wings and antennae of
this sex are relatively larger than those of the other
forms.

Fig. 6. — Under side of the head and part of sternum
of Fig. 5, showing the rostrum and first coxge.

Fig. 7. — Cornicle of the oviparous female.

Fig, 8. — Part of the head and the antenna of the
winged male.

PLATE XC.

C allLpter u s q,uer cixs .

(i.BB\uJiton. (Let et litJ-i . West KeufK-Mn,& Cyvmp

PLATE XCI.

Callipteeus queroeus. (Page 24.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Pale variety of the same, after moulting its
skin.

Fig. 3. — Winged viviparous female. The short
wings and the long body contrast much with the last
species.

Fig. 4. — The winged male. Here the wings attain
to a larger size.

Callipteeus castane^. (Page 26.)

Fig. 5. — Apterous vi^aparous female.

Fig. 6. — Pupa of the same.

Fig. 7. — Winged viviparous female. The anal valves
are much developed in all the winged females of this
genus. The disposition and number of the dorsal
pigmental spots are variable.

Fig. 8. — A leaf-bud of the sweet chestnut {Gastanea
vesca), with two ova adhering, which will remain
unhatched through the winter.

Fig. 9. — The ova magnified. Their form departs
from the usual oval, being attenuated at one end.

PIRATE XCI

L aliiptex'u.s o|ixerceiis 1—4'.
„ castajae'cE 5 — 9 .

OB Buck.ton drla.hth

West NewvMOLn & C tw^i

PLATE XCII.

Pterooallis alni. (Page 31.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Winged viviparous female.

Fig. 3. — Head and antenna of fig. 1. The front is
setose.

Fig. 4. — Head of fig. 2. The front is smooth, and
the smooth antennal joint curtailed in length.

Pterooallis juglandicola. (Page 32.)

Fig. 5. — Apterous viviparous female.
Fig. 6. — Pupa of the same drawn of relative size.
Fig. 7. — Winged viviparous female.
Fig. 8. — Viviparous female. The isolated spots on
the femora may be noted.

PLATE XCII

\

■ ' <y

X

4

.;

^*

^

/

rvl'A

Ptei"()i_-.i I iiis M.Iiil 1,-4-'.

,1 ;; vi.i.(laiiilici.)la 5 — 8

G-.B.J3u«l<-t<>n i*i-( fllWJ.

V\Vsl Ni'WMutil ^' l''"' :r'ii'

PLATE XCIII.

Pteeocallis TiLiM. (Page 34 )

Fig. 1 . — Apterous viviparous female.

Fig. 2. — Pupa of tlie same.

Fig. 3. — Winged viviparous female. The angular
form of the post-costal nervure of the lower wing may
be noted. The dark bands and spots in figs. 1 and 3
are inconstant.

Fig. 4. — ^Winged male. Perhaps the clouding on
the wings is most marked in this example of the genus.

PLATE XCIIL.

Pterocsdlis tilife

0:3.Bux:kton. dd ft loh

WestN^iYnui.i *('■' «7if

PLATE XCIV.

Phyllafhis fagi. (Page 37.)

Fig. 1. — Apterous viviparous female enshrouded in
long flocks of cotton-like substance.

Fig. 2. — The same insect denuded of this substance
by treatment with ether.

Fig. 3. — The oviparous female appearing in October.
The last rings are sparsely clothed with cotton, but not
represented in this figure.

Fig. 4. — Winged viviparous female. This insect is
both powdered and flecked with white filaments.

Fig. 5. — Apterous male, taken in company with fig. 3.

Figs, a and h. — Antennge of apterous and alate
viviparous females respectively.

Fig. c. — Head and short rostrum of imago (fig. 4) .

PLATE KCW.

.^.

^1

\

A

V \

"i

0. t>

V

3. •''^, •

•^2

A.

Pi lyl La p h 1 s i'a a i

I'i.Jiuol.-IOll t«^x-.r.l,U.I>l

WesI Nfcvvrii.ivii k-''' ...

PLATE XCV.

Ptychodes juglandis. (Page 40.)

Fig. 1. — Apterous viviparous female. The stout and
short legs, and the cornicles, seen as mere pores, may
be noted.

Fig. 2. — Winged viviparous female, the short an-
tennae and the narrow and peculiarly shaped wings are
characteristic.

Fig. 3. — Broad head of the apterous female with its
appendages. The three terminal antennal joints are
noticeable.

Fig. 4. — The last abdominal somites, showing the
short Cauda (fig. b) and the two vaginal valves (figs.
a, c).

Fig. 5. — Cornicle of the imago seen in profile.

PLATE XCV.

V/t/

z.

It -■ '■'..:■

^

c

fy^

i^r^f'

f ■•^" ^-1

.P-

r-Cf^^

.■^

IM

O.BJ3u<.-kton de/ci hth

P ty cKo cie s j uy La n d: s

West N«w)Fut»i £ C? vw.fl.

PLATE XCVI.

Lachnus jtjniperi. (Page 44.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Imago of tlie same. a. The tarsus with
the second joint more developed than in the foregoing
genera, b. Cornicle or nectary seen in profile.

Lachnus agilis. (Page 47.)

Fig. -3. — Apterous viviparous female.

Fig. 4. — Pupa.

Fig. 6. — Imago from the same. N.B. — The lineal
form of this and the next species contrasts with the
usual robust figure of other Lachninae.

PLATE XC\T,

s>^'

O l*'^

/

\

\

f' B Bocktorv cUd. et UiA.

La.oh.nu.s juniperi i

— 5 .

West -VomLa.?!, t C vwr.

PLATE XCVII.

Lachnus macrooephalus. (Page 48.)

Fig. 1. — Pupa sparsely covered with white powder.

Fig. 2. — Imago with the protruded rostrum. The
great length of the stigma is to be marked in all this
genus, a. Head and antenna of imago, h. Last
joints of the rostrum, c. Inverted view of the ano-
genital rings, e. Exit of the false vagina. /. Valves
closing the same. g. Clasping ring (*' armature copu-
latrice"). A part of the tail is seen above, d. Tarsus
with the second joint much developed,

Lachnus pini„ (Page 50.)

Fig. 3. — Apterous viviparous female.

Fig. 4. — Dark variety of the same. The globule at
the tail shows that the excretion of liquid is not, in
these insects, confined to the nectaries.

PiATE XCYLI.

'J-.B.BuWcton. dfl eliah.

• axiiiLus macT-ocepIialas 1--2 .
;. pini 3 — 4 .

West NeMiruw. £• .""mm

PLATE XCVIII.

Laohnus pinicolus. (Page 52.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Winged viviparous female. The long
stigma and the extended wings may be noted.

Fig. 3. — Young recently born from the imago.

Fig. 4. — Antenna of fig. 1. The tubercle (fig. a)
preceding the " nail " at the end of the sixth joint is
very usual.

Fig. 5. — Tarsus, with the hinged joint for the inser-
tion of the retractile muscle, seen at b.

PLATE XCVIII.

La-clinxis pinicolias-.

G .H .Bu.ekcan, del. tthtk.

V/eet.N^wma:n&.Ce. irnfi.

PLATE XCIX.

Lachnus viMiNALis. (Page 53.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Pupa of the same.

Fig. 3. — Imago. The tubercle seen between the
cornicles in the previous forms is here wanting.

Fig. 4. — Imago, showing the wings folded horizon-
tally whilst at rest. This position, however, is not
always assumed by the wings.

Fig. 5. — A portion of willow bark infested by the
above Aphis. Alarm is shown by the jerking upwards
of the hind legs of the insects.

Fig. 6. — Dorsal papilla. The apex shows the ori-
fices of minute vessels, which probably secrete some
liquid, disgusting to the parasites which hover over the
infested branches. The winged insects, by their
activity, are less open to the attacks of Syrphus,
Coryna, &c., and therefore they are not provided with
this gland (?).

PLATE aCIX.

La^chniis vixniaalis

G B.Buthtort. del.etTith-.

West.T^eiW^mci^n.ScCo.irytpi

PLATE C.

Lachnus PiOEiE. (Page 58.)

Fig. 1. — Apterous viviparous female, a. The long
rostrum in situ.

Fig. 2. — The rostrum much magnified, with details
of the antennge. b. The sheath with its very long
setas. c. The labrum.

Fig. 3. — The sixth and part of the fifth antennal
joints, d represents the tubercular rings much mag-
nified. Suggestions as to the functions of these drum-
like orifices may be found on page 13, vol. i, of this
Monograph.

Fig. 4. — Enlarged view of a sprig of the spruce fir,
crowded with the polished eggs of the above Aphis.

PLATK C.

La.c h

cnnus picc£c.

A ."B .'Bvuiktci-i ci«l . ei'liih .

.->M-«;rj ^Co. v*Mp.

PLATE CI.

Laohnus longipes. (Page 59.)

Fig. 1. — Winged viviparous female. Perhaps this
insect has the greatest expanse of wing of all the
British Aphididse. The antennsB, on the other hand,
are very short.

Stomaphis quercus. (Page 62.)

Fig. 2. — Apterous viviparous female, r. The ros-
trum protruding beyond the apex of the body.

Fig. 3. — The same viewed from the underside. The
great strength of the sheath near the head is here
shown, i. Labrum and the fine setae. These last are
the representatives of the labium and the maxillae.

Fig. 4. — Head and antenna of fig. 1.

Fig. 5. — Head and antenna of fig. 2.

'I.ATR C

- T

1 ,ae hnus iongipes
L n-\ a. p h I s q, a G r c u s

,.2-

G li Bu-ekion, d^. el Ulh-

JVe* t, Nt.vr-rvui;n ^ Co '>n7> .

PLATE CII.

Lachnus cupresst. (Page 46.)

Fig. 1. — Apterous viviparous female.

Fig. 2. — Pupa from the same.

Fig. 3. — Imago, a. Cornicle of fig. 3 with bristles
surrounding its base. h. The same viewed from above,
showing the mouth of the nectary, which is capable of
being closed by a contraction of the external lips.
These figures are unavoidably somewhat out of their
proper sequence. Lachnus cupressi is more nearly
allied to Lachnus juniperi.

Paracletus cimiciformis. (Page Q^ .)

Fig. 4. — Apterous viviparous female. c. Head.
d. Antennae.

Trama troglodytes. (Page 68.)

Fig. 5. — Apterous viviparous female. The pale
hairy variety.

Fig. 6. — The same before a moult. The stout
rostrum is represented at r. Notice may be taken of
the characteristic sm^Ze- jointed tarsus, which has a
considerable length.

Fig. 7. — Young born from fig. 6. At this age the
rostrum much exceeds the length of the body.

PLATE CLI.

X

\

rl, %

c:;^

LT

J/

/

\

'• B Bn<:/<ti>>L d(.eJ rtUUv

La.chnus cixpressi 1-^3.
Paracletiis ciirLici£orjn.is 4

Tz-ajna tToglodytes 5—7,

Wi^stNev/Tn<i»i i'-

PLATE cm.

Dryobius roboris. (Page 71.)

Fig. 1. — Apterous oviparous female, h represents
the egg which she has laid, wliich is not strictly ovate,
but inflected at the side. Unlike that of B. croaticus
the egg is smooth and shining.

Fig. 2. — The winged male. The larger wings and
lighter body permits more activity than that shown by
the female.

Fig. 3. — Front view of the apterous viviparous
female, standing on a leaf, and showing the short
proboscis and long hind leg.

Fig. 4. — Abdominal segments of fig. 2, showing the
excerted and curved male organ.

Fig. 5.* — A leaf of Quercus ilex from Montpellier.
The upper surface is occupied by a patch containing
about two hundred eggs of Dryobius Croaticus, ranged
with a certain regularity, with all their ends turned
one way. This patch probably was the work of ten or
more females, since several dead bodies of these were
found adhering to the leaf. These eggs were all placed
upon the upper surface of the leaf, and to protect them
from rain they had for a covering an insoluble varnish.
Unfortunately I failed in my eff'orts to hatch these
eggs in the following spring.

* This figure 5 should have been drawn on Plate CIV.

PLATE cm

Dryotius rolooT'is,

GJB.BwMcr^ oLel. tk. Uik.

fyi3t,N^e-Vf'**ux:n&..Co.-i^frif> .

PLATE CIV.

Dryobids Ckoaticus. (Page 74.)

Fig. 1. — Apterous viviparous female. Attention
may be drawn to the long legs and slender antennae.

Fig. 2. — Winged female with its small wings and
disproportionately large body.

Fig. 3. — Antenna and eye of the same.

Fig. 4. — Conical nectary rising from a dark areola.

Fig. 5. — A portion of one of the dark fascia of the
wings, much enlarged. Two membranes are seen to
overlap each other, but the hexagonal cells do not
coincide. The pigment is confined to the peripheries
of these cells.

Fig. 6.* — A portion of the bark of Quercus rohur
on which the female of Dryobius rohoris has just
laid three rows of eggs. These at first are white,
but by exposure to the air they soon become brownish-
black and velvet-like.

* This figure 6 should liave been grouped with the last-described
species.

PLATE CIV.

Dryobivis croa.tiG"as

a.'B.SiJ.dit-o-n lUl ,<^ hSi-

We-stJ^ftw^yiX^-n &. Co ifvrp

PLATE CV.

SCHIZONEUEA LANIGERA. (Page 89 .)

Fig. 1. — Apterous viviparous female, witli her
young clotlied witli cotton-like fibres. This is the
adult form of the young produced from the next
insect.

Fig. 2. — The Queen Aphis or foundress of the
colony with her young.

Fig. 3. — The pupa, which is almost naked of down.

Fig. 4. — Brown variety taken on the bark of the
apple tree, December 5th, whilst the thermometer
showed 20° Fahr. Snow on the ground.

Fig. 5. — AVinged viviparous female.

Fig. 6. — Antenna of the same.

PLATE CV.

/■'i-

^

^^^,«*a«--*«.,«^_

Sclxiz oixeixra la.ixiaex'a.

GB.BiKjcton !lel ethtk

WesiMewmom. Sc C? iw-B.

PLATE CVI.

SoHizoNEURA LANiGERA — continued. (Page 89.)

Fig. 1. — Rostrated apterous male.

Fig. 2. — Non-rostrated oviparous female. Tliese
two figures are of relative size to tlie winged female
whicli bore them (see fig. 5 on last plate).

Fig. 3. — Head, antennge, and aborted mouth-parts of
the oviparous female. No trace of a sucking organ can
be seen. The antennee also are degraded in form.

Fig. 4. — Young (male ?) born also from fig. 5.
The rostrum would seem to disappear at the subse-
quent moult. This sex therefore is finally blind as
well as mouthless.

Fig. 5. — Sprig of apple bough, tufted with the
" American blight," drawn of natural size.

SoHizoNEURA FODIENS. (Page 94.)

Fig. 6. — Apterous viviparous female.

Fig. 7. — Pupa from the same. Both of these are
subterranean forms.

Fig. 8. — Imago with her folded wings, drawn shortly
after she has left the colony below ground.

Fig. 9. — Young just born from the winged female.
The legs are hardly yet disengaged.

Fig. 10. — Upper and lower wings of imago.

Fig. 11. — Portion of the root of Ribes (black cur-
rant) infested by this Aphis. Nat. size.

Fio;. 12. — Antenna of the same.

PI. ATE C"vr.

\-

I^V'"^

ry:0m^[xm^^^^^'^'^^<^

f^#r;^oC

Sdiizojrxeura lanicjera,. Fig. 1—5.
fodieias . -Fi-_^. 6-12.

■.B Sxuktorvdel ethiK.

'iVe.st.Newmcm S: C° imfi^

^

PLATE CYII.

ScHizoNEUEA FULiGiNOSA. (Page 96.)

Fig. 1. — Pupa covered by its tomentose coat. It is
ratlier greyer in nature than is here represented by the
figure.

Fig. 2. — Winged female of the same.

Fig. 3. — Apterous male, drawn under the same mag-
nifying power as the former insects. Captured early
in November.

Fig. 4. — Female taken in company with the last,
perhaps the perfect-sexed female, l^ot quite so small
as the male.

Fig. 5. — Head and antenna of the imago.

Fisr. 6. — Part of a leaf of Pinus austriaca, with
young Aphides feeding thereon. Usually they range
themselves in a long file, with their heads placed in
one direction, a. An ovum of one of the Syrphidce
secured to the pinna by several silken mooring threads.
h represents the outer covering of this egg^ much mag-
nified, in which the pores of the membrane are seen to
be continued and expanded into corrugated trumpet-
like mouths. The whole shell is covered by these
stomata, and they form an interesting object for the
microscope. The aeration of the ovum, doubtless, is
effected through these openings. I have not been able
to prove whether they close hygrometrically or not.
The egg becomes beautifully transparent by soaking in
weak glycerine, and it then shows a footless grub
within.

Scceva pyrastris is said to live ten or twelve days in
the larval condition, and about fourteen as a quiescent
pupa. The existence of the imago may be prolonged
to six weeks. These ova are not uncommon in the
vicinity of such Aphides, which constitute the food of
the voracious maggots that hatch out of them.

PI.ATE CVIL

2.

^:^.

h.

^^

^>.

Scliiz oneixrsL faliqirLo sa. .

PLATE CVIII.

SoHizoNBDRA uLMi. (Page 97.)

Fig. 1. — Queen Apliis. The produce from an egg.

Fig. 2. — Head and antenna of tlie same. a. Coxae.
h. Small rudimentary eye, composed of eiglit or ten
facets only. The antenna has only four joints.

Fig. 3. — The imago extricating itself from its pupal
integuments, and shedding all its woolly coat at the
same time. The limbs and wing-cases at first are very
transparent.

Fig. 4. — Mature imago with young. The last-born
foetus has not disengaged itself from its investing
membranes.

Fig. 5. — Leaves of the elm, rolled and blistered by
the Aphides, which nest within. The winged insects
are represented of their natural size.

Fig. 6. — Globules of (fsecal ?) matter interspersed
with mealy powder, being part of the contents of the
above rolled leaves, c. Membranous fragments which
remain after these globules have burst.

PLATE CVm.

.3 SvLckton, del. et lu}i

Scliiz oxieura. iiiirLi.

W»fjfi Ucwyn<A.>-i :•>. v'" n*tf-

PLATE CIX.*

SoHizoNEUEA ULMi (continued). (Page 97.)

Fig. 1. — Young Apliis born from tlie Queen Aphis.
Fig. 2. — The same matured.

Fig. 3. — Antenna of the apterous viviparous female
(fig. 2).

Fig. 4. — Antenna of the winged viviparous female.

SCHIZONEURA LANUGINOSA. (P. 104.)

Fig. 5. — Part of the third, and the whole of the
fourth, fifth, and sixth antennal joints of the imago of
the first alate generation.

Fig. 6. — The apterous viviparous female.

Fig. 7. — The pupa.

Fig. 8. — The imago seen in profile, which has placed
its wings pentwise whilst at rest. The small size of
these insects is due to their being examples of the last
alate generation.

Fig. 9. — Antenna of fig. 8, showing a modification
of fig. 5, the second alate generation.

Fig. 10. — A twig of elm (JJlmus campestris), one
third of the natural size, with purses constructed by
Schizoneura lanuginosa, gathered at Cambridge, August
7th, 1871. The galls were full of pupae and winged
insects ready to emigrate.

* The lettering on this place is an error. For figs. 1 — 5 read 1 — 4,
and /or figs. 6 — 10 read 5 — 10.

P_LATE CJX.

■■■^-W

-^> -^■■

chizoneura -alim , F'i^ . 1—5.

„ la-Tiuqiiiosa Fiq. 6—10 .

C, R Bn.iftondcl tflith.

West Ncvfyrvcui XC^ vmp

PLATE ex.

SoHizoNEURA coRNi. (Page 107.)

Fig. 1. — Winged viviparous female.
Fig. 2. — Apterous male.
Fig. 3. — Oviparous female which is eyeless.
Fig. 4. — Antenna of the imago plentifully supplied
with tubercles.

Pemphigus fuscifrons. (Page 113.)

Fig. 5. — Apterous viviparous female.

Fig. 6. — Pupa. The cotton-like tufts occur in
isolated bunches.

Fig. 7. — The imago. Attention may be called to
the veining of the under wings.

Fig. 8. — The oviparous female crowded with ova.

Fig. 9. — Antenna of the imago.

PLATE CX

G-.B.Bxi r'kl-tTn,, SA. ctUth

Sclii zone lira cox-ni. F-og.l — 4.

Pempliigiib fuscifroTiS. Fvq. 5^3.

West Nrvfnvaji. Sr, d'lmp.

PLATE CXI.

Pemphigus bursarius. (Page 117.)

Fig. 1. — Queen Apliis — apterous female.

Fig. 2. — Pupa with circular wliite mealy patches,
like the above queen.

Fig, 3. — Imago, with young, which last have by
some been mistaken for ova. The angular veining of
the hind wing differs from the foregoing species.

Fig. 4. — Leaf of poplar, the foot-stalk of which has
been punctured by the Queen Aphis. Two purses are
here formed with corrugated openings, through which
the winged females escape. This form of gall is
thought by Lichtenstein to be the work of a species
which he proposes to call P. pyriformis. He con-
siders the round gall (PI. CXIII, fig. 7) to be the work
of Pemphigus bur sarins.

Fig. 5. — Section of a pyriform gall, natural size,
showing within the cavity the Aphides covered with
mealy dust.

Fig. 6. — Antenna of fig. 1.

Fig. 7. — Antenna of imago (fig. 3).

Pemphigus spirothec^. (Page 122.)

Fig. 8. — Apterous viviparous female, covered with
white down.

Fig. 9. — Bottle-like gall, found on the stem of the
black poplar {Populus nigra). Probably an abnormal
form, and the work of Pemphigus spirothecce. The
normal spiral " galls " are represented in PL CXII,
figs, i— 3.

PI.A.TE cxr.

Penopliigus t-Lirsariu-S Frq.l—V.
„ spirotkecoe Fiq . 8— 9 .

C B.Bu^tor. ficZ (»j^ tjjh

^^njst, "i^pj^^ivhoun. S: C^ i^yip.

PLATE CXII.

PEMPniGDS spiROTHEOiE {continued). (Page 122.)

Fig. 1. — Leaf and foot-stalk of Populus nigra. A
winding cavity has been formed, which is more or less
blistered by the sucking of the Aphides.

Fig. 2. — The same construction viewed sideways.
s. The opening.

Fig. 3. — Another example, better showing the spiral
contortion of the stem. By a gentle strain the foot-
stalk stretches and opens hke a helix, s. The opening.

Fig. 4. — The oviparous female with her single
included egg.

Fig. 5. — The non-rostrated apterous male. p. The
penis.

Fig. 6. — The head and simple antenna of the ovi-
parous female.

Pemphigus lactuoarius. (Page 124.)

Fig. 7. — The nearly naked viviparous female (queen?).

Fig. 8. — The same in a more adult form, with long
curls of cottony fibre.

Fig. 9. — Head, antennae, rostrum, and eyes of fig. 8.

Fig. 10. — Antenna of the adult form.

Fig. 11. — Vermiform larva, possibly representing an
ancestral type. The point of the rostrum may be seen
protruding on one side.

Fig. 12. — " Degraded" head and antennae of fig. 11,
with almost obsolete eyes.

Fig. 13. — Section made through a clod of earth, and
thus exposing a cavity tenanted by P. lactucariiis.
Natural size.

PLATE CXII.

// -n

^^S^Sf^'^<

&.B.Bucl<ton. del et> Uth:

Pemplii^as spirotliecas Fi^ . 1 — 6.
11 la.ctuca.rius. F'^ ■ 7 — 13.

yftstNewmxux, &'C?ijrtp.

PLATE CXIII.

Pemphious pallidus. (Page 127.)

Fig. 1. — Queen Aphis or foundress.

Fig. 2. — Pupa.

Fig. 3. — Imago. The stigmata are pale emerald
green, with a dark internal spot.

Fig. 4. — Antenna of the Queen Aphis with its isolated
tubercles.

Fig. 5. — Gall formed on the midrib of ulmus.

Pemphigus buesarius. (Page 117.)
See also Plate CXI, figs. 1—7.

Fig. 6. — Queen Aphis, showing the small legs and
antennae of the insect.

Fig. 7. — Part of a small branch of poplar, on the
woody portion of which a rugose gall has been con-
structed, with two openings, one at the top and the
other at the side o o. This and some other pseudo galls
were sent to me by M. Lichtenstein with the remark that
he considered them to be the work of P. hnrsarius,
whilst the pyriform galls he considered to belong to a
different species. In this uncertainty, I prefer simply
to call attention to their different forms, and not to
name the insects on my insufficient knowledge. The
imagos which issue from these galls are very like
the British insects, but they show some modification
in the form of their antennal joints.

Fig 8. — Antennal joint of imago from gall (fig. 7).

PLATE CXIII.

Peniptiig-as pallidas . Fi^. 2
„ "burs anus. Fvq. 6

G-B.Bujckton- del: tit lith-.

- 5.

West Newman- Sc C? irrvp.

PLATE CXIV.

Pemphigus filaginis. (Page 128.)

Fig. 1. — Winged viviparous female with tlie body
sparsely dotted witli down.

Fig. 2. — Semi-transparent oviparous female.

Fig. 3. — Head and appendages of tlie last insect.
d. The processes representing the mouth parts, e.
The rudimentary eye.

Fig. 4. — Antenna of the imago.

Tetraneuea ulmi. (Page 131.)

Fig. 5. — Queen Aphis, just turned out of the gall
(fig. 12).

Fig. 6. — Second brood of the winged females. She
has just borne an oviparous female (fig. e), which is
drawn of the relative size.

Fig. 7. — Antenna of imago.

Fig. 8. — Non-rostrated oviparous female, much
magnified, with her gigantic egg. d. Buccal parts.

Fig. 9. — Antenna of oviparous female.

Fig. 10. — Young born together with about thirty
others from the spring brood of a winged female, a.
The rostrum, h. the last joint.

Fig. 11. — Upright pedunculated gall, natural size,
springing from the midrib of Uhnus tuberosa.

Fig. 12. — A gall slit in half, showing the Queen
Aphis within.

Fig. 13. — Another gall springing from the mem-
branous portion of a leaf. The gall is empty, but
several winged females are flying above it.

PLATE CXiV.

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