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sylvestris. Li/da stellata, L. erythrocephala.
b.' Reddish larvae. Lyda pyri.

B. Solitary larvae.

a. Living in folded down leaves on birch and poplar.
L. sylvatica ; on alder, L. depressa.

b. Living on the rose in a case formed of pieces of
leaves. L. inanita.

There is one other point in connection with the color-
ation of the larvae which requires to be noted ; namely,
the striking change in coloration which many of them
undergo immediately before pupating. In most cases
the change is in the direction of a more obscure
generally green coloration. Of this we have a good
illustration with many species of Nematus. Other
species become brownish, or slate-coloured, while with
one or two the change of colour is towards a brighten-
ing of the tints. Along with the colour, all hairs,
spines, &c., are thrown off, so that the difference between
the two skins is often so great that very often the two
forms are taken to belong to two distinct species. The
reason of the change of dress seems to be this : When



54 CHANGE OP COLOUR IN LARVJ3.

the larva has become full fed, it has to go in search of
a suitable place wherein to pass the period of rest un-
disturbed ; and this cannot be had on the food plant.
Many of them pupate in pithy stems, without spinning
any cocoon, while others seek such situations because
their cocoons are thin. Hence they may have to travel
some little distance before finding a proper place a
fact shown by finding their cocoons in stems, or under
bark, many yards distant from the food plants. Now,
when a larva descends from the food plant, it enters
on a new mode of life, comes in contact with dangers
to which it had not been accustomed to, and meets with
new enemies. Thus a more obscure coloration would
be of advantage, and that it is of use, I have observed
with Nematus viminalis, which becomes slate-coloured
before leaving the galls to pupate in the ground the
slate-colour harmonising admirably with the sand on
the river-banks where it lives as it does with the
dried grass, &c., found in the meadows where other
gall-making species of similar habits live. With
Cladius viminalis, again, the colour at the last moult
becomes more brilliant. In this case several larvae
live on a leaf side by side, and thus they are made
visible ; but when they become full fed they separate
to seek a hiding place, which is generally under the bark
of a growing tree, up the trunk of which they march.
The increase of brightness in the colour thus is of
advantage, as it makes the larvae more readily seen,
and seen, avoided, in the case of inedible larvae.

A few larvae would appear to be dimorphic. The
larva of Nematus caprece is mostly green, with white
longitudinal lines, but there is a rare form of it with
the body reddish. One or two species of Cimbex appear
to have dimorphic larvae also, but the subject requires
further investigation.

When the larva has become full fed, it proceeds
to pupate. Some larvae spin no cocoon, but bore into
the pithy stems, or into holes made by beetles in
wood. Others form in the ground neatly rolled cells



THE PUPA. 55

of earth, but most species spin oblong silken cocoons.
The species of Selandria, &c.,mix the silk with grains
of earth. The Cimbicides spin double cocoons, an
inner one inside an outer more tenacious covering,
the inner one being separated from it by a clear
space. Some species of Nematus likewise form double
cocoons, but not all. Those of Cladius are irregular
in shape, thin, and almost transparent. The outer case
of the cocoon of ClaveUaria is also of an open texture.
Cinibex and Trichiosoma spin their cocoons on the
branches of the food plants ; Nematus gallicola in
masses under chinks of bark on the food plant,
( ' njptocanipuspentandrce in the galls ; but most species
spin them in the earth.

After being in the cocoon the larva in a short
time shortens and contracts its shape, the legs at
the same time being withdrawn into the skin as it
were. The period which elapses between the spinning
of the cocoon and becoming a pupa varies according
to the season. "With the summer broods it may be
from seven to ten days, but the autumnal broods do
not change until the following spring, so that the
greater part of their larval existence is spent in this
inert condition. In exceptional cases they may even
remain two years in the cocoon before changing.

The larvae are very much preyed upon by ichneumon
and dipterous flies (Taclima and its allies). The ich-
neumons belong principally to the Tryphonides, which,
indeed, would appear to be specially attached to saw-
fly larvae. Braconidce are not often bred from them ;
the Ophionides are not uncommon, while many Chalci-
didce as well as Pimplides are reared from the gall-
making Nemati.

The Pupa

Bears a considerable resemblance to the perfect insect.
The antennse are placed along the front, the legs along
the breast, while the wings appear as pad-like struc-



56 GENERIC DISTINCTIONS.

tures. Each appendage is enveloped in a thin pellicle.
Green is the commonest colour in the pupal state.
Sometimes there are yellow or orange spots on the
abdomen, but only if these colours were present in the
larva. The pupa state does not last over twelve or
fourteen days, as a rule, and may be shorter. When
the perfect state is reached the insect does not leave
the cocoon until its wings, &c., have hardened, and
the pupal skins have been got rid of. It quits the
cocoon by cutting off one end, which is done in
Nematus, &c., by cutting out the end roughly, but
with Lophyrus and Oimbex a neat lid is cut, which
remains attached to the cocoon by one end after the
insect has left.

Generic and Specific Distinctions.

It must be said that it is not at all an easy matter
to find characters that will differentiate clearly the
larger groups and the genera, and even if we are able
to do so with European species difficulties arise when
exotic species are taken into account. Thus, Strong y-
logaster and Selandria are tolerably distinct and well
defined if we only regard our own species, but when
we come to arrange the Central American species all
distinction between the two breaks down. Similarly,
by following too closely the alar-cell structure in
fixing the genera species otherwise dissimilar are
placed together, and removed from among species
with which they agree in other peculiarities of struc-
ture.

Peculiarities in the antennae, thorax, legs, and
abdomen appear to afford the best characters for
defining the tribes. For the sub-tribes the neuration
of the wings is of use. The genera may be defined by
peculiarities in most parts of the body, but more
especially in the (a) antennae, as regards the number
of the joints, their relative length, and their covering;
(b) the neuration of the wings, and more especially the



GENERIC AND SPECIFIC DISTINCTIONS. 57

number of the radial and cubital cellules, the number
and position of the recurrent nervures, the form of the
lanceolate cellule, the form of the neuration, and the
number of cellules in the hind wings. It will depend,
however, very much on the group as to what value
will be placed on any particular nervure or cellule.
Thus, among the Nematina the first cubital nervure
is often absent, either constantly in particular species
or groups or occasionally with certain species, but its
absence occurs in so many widely separated groups
that no generic value can be placed on it. In the
same way the posterior wings may have either one or
no median cellule in different species in a genus, and
even in different sexes of the same species, (c) The
structure of the legs, i.e. whether they are armed with
spurs or spines, provided with patellse or not, the
nature of the trochanters, coxae, tarsi, &c. These I
consider to be the characters of most value, but other
parts of the body occasionally afford distinguishing
points. For example, the form and position of the
eyes, of the clypeus and other mouth organs, the
structure of the thorax and abdomen. In some
instances the ovipositor can be used for the same
purpose.

The larvae can be also used in classification. In
this respect they are of great value in defining the
tribes and subtribes. They do not appear to be of
much use with the genera. A few genera, indeed,
have well-marked larvae, but in most cases their forms
are too much of an adaptive nature to furnish generic
characters. Thus, with Eriocampa we have slimy
larvae, slimeless larvae, and larvae covered with a white
flaky substance. Both Hoplocctmpa and Blennocampa
have spiny larvae ; in Nematus they are of all shapes
and colours ; while no distinction can be drawn
between the larvae of Tenthredo and Allantus or even
Dolerus.

The discrimination of the species is often very diffi-
cult. Colour is the distinguishing mark which most



53 SPECIFIC DISTINCTIONS.

readily catches the eye, and undoubtedly it is a valu-
able character, always provided that other points are
not ignored, as unfortunately they too often are in
descriptive works. The body is rarely sculptured,
sometimes it is more or less pilose, but excellent
characters are to be obtained from the antennae, as to
their length, thickness, pilosity, &c. ; of the clypeus,
as to whether it is truncated or incised at the apex ;
by the form of the head and its sutures; by the
arrangement and position of the nervures in the
wings ; by the legs, as to the length of the spurs, of
the tarsal joints, and the form of the spurs. Most of
the specific characters, in fact, are slight morpho-
logical variations, which, so far as we can see, are of no
use to the species ; but in one organ we find a wonder-
ful amount of variety in structural detail. This is in
the saw, of which, indeed, it may be said that its form
affords us an almost infallible criterion of specific
distinctness. We can easily see why there should be
so much variety of form in the saw when we consider
not only how manifold are the modes of depositing the
ova, but also how different in texture, &c., are the
substances in which they are laid. And as the same
species follows always the same mode of oviposition we
can understand, also, how this organ scarcely or never
varies in structure ; for a variation, however slight in
the shape of the teeth, &c., might prevent the eggs
being sunk in the proper manner in the substance of
the leaf, and thus might lead to the death of the
embryo. Contrariwise, we find great variation in the
other specific distinctions in colour, sculpture, &c.,
because they are, so far at least as we can see, of
secondary importance to the insects, and therefore
variation has had some play.



DISTRIBUTION. 59

3. DISTRIBUTION.

The Tenthre din idee must be regarded as inhabitants
of temperate, if not northern climates. This is more
particularly the case with the Nematina, which are
found as far north as Spitzbergen and Iceland, abound
in the northern parts of Europe, but become very
scarce towards the Mediterranean. Thus, Scotland
lias about seventy species of Nematus, and Italy only
twelve, according to Costa, or a half more than what
Iceland has. The Tenthredina are more widely distri-
buted, being found commonly in the Palaearctic, Neo-
arctic, and Oriental regions. The Cimbicides are
natives of the Neoarctic and Palaearctic regions, into
which they penetrate pretty far north. Other tribes
are peculiar to the Neotropical and Australian regions.
As for the Hylotomina they are in great force in the
Neotropical, and not uncommon in the Palsearctic and
Neoarctic districts. Lyda seems to be confined to
Europe and North America, although it is likewise
found in Northern China.

A few species have a very wide range ; thus, Hylo-
tnma pagana is found in America, all over Europe
into India and Japan. Many species are common to
Northern Europe and America, e.g. Hemichroa rufa,
Xi'matus histrio. Athalia has, for such a small genus,
a very wide range. The common turnip species (A.
xj'iiuinim) abounds all over Europe, from Lapland to
the shores of the Mediterranean, and through Asia into
Japan. Another species is found in South Africa,
which would appear to be singularly poor in Tenthre'
dinidce.

4. COLLECTING AND PRESERVING.

For collecting these insects, a sweeping net and
an umbrella for holding under bushes which are beaten
into it are the most useful. They are to be sought
for along hedges, the borders of fields, in marshy places



60 COLLECTING AND PRESERVING.

for some Doleri and Nemati, and in woods containing
oaks, birches, willows, and poplars. The sweeping
net is of most use during the day when beating,
especially if the day be bright and warm, produces little,
for they fly away the moment the trees are touched.
If the weather be dull, however, beating may be
employed advantageously, as it can always be done in
the evening.

They maybe either pinned or mounted on cardboard.
If pinned, and not set properly, the wings should be
separated in such a way that the neuration can be
easily examined. If the carding method be followed,
the insects should be mounted in such a way that the
form of the clypeus can be seen, and the hinder tarsi
should be loose, so that the form of the claws can be
conveniently seen. It is better, too, to have at least
one specimen with one wing not gummed down.

The saws are best prepared for microscopical exami-
nation as follows : They are extracted from the
abdomen by pressing its sides, when they will project,
and be easily cut off. The pieces should then be
separated and steeped in turpentine for a day or two.
Take a sheet of thin Bristol board, cut it into pieces,
say six lines by nine, then punch in one end of this a
round or square hole, say two and a half lines across.
Next, fasten to one side of this hole a microscopic
cover glass by means of Canada balsam dissolved in
benzine. After this has dried, fill up half of the cell
thus formed with balsam, spreading it as evenly as
possible. In this arrange the parts of the saw, set the
preparation aside for a day, then fill up with balsam
until the cell overflows, and put on another cover glass.
All that now remains to be done is to keep the pre-
paration in a flat position until the balsam has dried,
after which it is labelled and a pin stuck through
the cardboard, by means of which it is placed in the
cabinet along side the insect from which the saw was
taken.

For the examination of the saw a quarter-inch



CLASSIFICATION. 61

objective is the best ; if lower powers are used some of
the details are apt to be overlooked. The mouth
organs and other portions of the body can be mounted
in the same way.

The larvae may be reared in the customary methods
followed by lepidopterists. Owing to so many of them
remaining over the winter as unchanged larvae, they
are not always easily reared, but no special difficulties
are met with in dealing with the summer broods,
which pass rapidly through the larval and pupal stages.

They may be preserved for the cabinet by holding
them, after being placed in a pill box which is enclosed
in a tin canister, over the flame of a paraffine lamp or
over the gas for a minute or two, when they will
become perfectly hard. If proper care be taken, fairly
satisfactory specimens may, by this plan, be obtained,
provided that only fully grown specimens, with empty
food canals, are operated upon. The preserved larvae
are perhaps kept best on pins stuck through cardboard,
another and stronger pin being stuck in this, and by it
kept in position in the cabinet.



5. CLASSIFICATION.

The first who attempted the classification of the
Tenthredinidce on an extensive scale was the English
naturalist, W. E. Leach (Zoological Miscellany, vol.
iii). He divided the family into nine " stirpes,"
two of which were grounded on Australian forms.
Stirpe 1 contained C-imbex, Trichiosoma, Clavellaria,
Zarcea, and Abia. Stirpes 2 and 3 were formed for
the Australian genera Perga and Pterygophorv* re-
spectively. Stirpe 4 had one genus, Lophyrus^ 5 two,
Hylotoma and Cryptus ; 6 had four, Messa, Athalia,
Selandria,aiidFemi,8a; 7 included Allantus, Tenthredo,
Dosytheus, Dolems, and Emphytus ; 8 Coeesus and
Neinatus; and 9 Tarpa and Lyda. Saint Fargeau
(Mon. Tenth.) had an arrangement of his own, but,



62 OLASSIFICATION.

as it is very artificial, it is unnecessary to allude to it
further here. The Swedish entomologist, Dahlbom
(Prod. Hym. Sc.), arranged the Swedish species in
fifteen genera, namely, Cimbex, Athalia, Hylotoma,
Cyphona, Lophyrus, Monoctenus, Cladius, Priophorus,
Nematus, Tenthredo, Dineura, Emphytus, Dolerus,
Phyllotoma, Lyda.

James Francis Stephens, in vol. vii of his c Illus-
trations of British Entomology,' described all the
British genera and species known by him to inhabit
Britain. This work, however, was by no means a
critical one as regards the discrimination of the species,
but as he gave, in most cases, the original descriptions,
many of which were not readily obtainable, it was, on
the whole, a work of some utility to the British
Entomologist. Stephens' classification was as fol-
lows : Cimbex with 8 British species, Trichiosoma 9,
Clavellaria 2, Zarcea 1, Abia 2, Amasis 2, Hylotoma
15, Schizocerus 2, Lophyrus 3, Cladius 1, Pristiphora

9, Nematus 45, Croesus 3, Mess a 1, Fenusa 3, Athalia

10, Selandria 40, Hemichroa 3, Sciapteryx 1, Allantus
47, Tenthredo 28, Dosytheus 14, Dolerus 9, EmpJiytus
20, Heterarthrus 1, Melicerta 1, Tarpa 2, and Lyda 21
species, or a total of 309 British species.

Hartig (following Klug), in his ( Blattwespen/ dis-
tributed the species into thirteen " genera," and each
genus was again divided into sub-genera, these into
66 sections " and the " section " into " tribes." Each
division received a name, so that, on this arrangement,
the nomenclature of a species was rather cumbersome.
Thus the Tenthredo albipes of Linne became Tenthredo,
Allantus, Selandria, Blennocampa, Monophadnus al-
bipes. In fact, his * 6 genera " are equivalent to the
"tribes" of recent authors; and his sections and
tribes have become genera. He arranged the genera
(= tribes or sub-families) thus : Cimbex, Blastico-
toma, Hylotoma, Lophyrus, Cladius, Nematus, Dineura,
Dolerus, Emphytus, Tenthredo, Tarpa, Lyda, Xyela.

"Westwood (Introd., ii, 113) introduced an improve-



CLASSIFICATION. 63

merit in the classification of the family by dividing
it into named sub-families. Of these he made four :

" 1. Cimbicidcs. Antennae short, clavate, with not
more than eight joints, larvae 22-footed, emitting
drops of viscid matter from the pores of the body
(Cimbex, Perc/a, fyc.).

" 2. Hylotomides. Antennae 3-jointed, terminal
joint greatly elongated, labrum apparent, larvae with
eighteen to twenty legs, not emitting drops of viscid
matter (Hylotoma).

" 3. TentJvredinides. Antenna 9- to 14-jointed,
simple, filiform to the tip ; labrum apparent, saws
with parallel sides (Tenthredo, Nematus, Dolerus, Se-
landria, &c.).

" 4. Ly elides. Antennas multi-articulate, sometimes
strongly pectinated in the males ; posterior tibiae
often spined in the centre ; labrum minute, saws but
slightly serrated at the tip, strongly dilated and
elbowed at the base, larvae various (Lyda, Tarpa, and
Lophyrus)"

Athalia was stated to form a connecting link between
the Hylotomides and the Tenthredinides, while Cephus,
Xyela, and Blasticotcftna were indicated as worthy of
elevation into sub-family rank.

C. G. Thomson (Hymen. Scand., i) has carried
out still further Westwood's idea. He grouped the
genera into seven tribes : Cimbicwa, Hylotomina,
Tenthredina, Blasticotomina, Lydina, Xyelina, and
Cephina. In thus distributing them he relied prin-
cipally on the form of the antennas, legs, and
abdomen.

Zaddach (Schr. Ges. Konig, xvi) has separated
Nematus and its allies from the Tenthredina, among
which they were included by Thomson, and formed them
into a distinct sub-family. He seems also to indicate
that Lophyrus should form a tribe, or at any rate that
it should not be united with the Tenthredina.

The fact that Nematus and its allies have, as larvaa,
only twenty legs, while the Tenthredina have twenty-



64 CLASSIFICATION.

two, is an important distinction ; yet it is very diffi-
cult to find characters to separate the two divisions
in the perfect state. Hoplocampa might, for example,
be ranged with Dineura, with which it agrees in the
form of the antennas and in the position of the basal
nervure, while it differs in both of these points from
Blennocampa, &c. The only absolute distinction is
that the second cubital cellule receives both recurrent
nervures in the Nematina.

Lophyrus appears to me to possess sufficient distinc-
tive characters to merit its being formed into a tribe.

As to the grouping of the tribes I certainly think
that the affinities of Lophyrus are with Tarpa and
Lyda rather than with the Tenthredina. Its relation-
ship with Cladius, near to which it is more often
placed, is not very great ; the similarity of the an-
tennae in the males, so far as it goes, cannot be
regarded as of great value, being merely a sexual
character. Pterygophorus, again, unites Lopliyrus with
Hylotoma, as does also Brachytoma, and one or two
undescribed genera known to me. On the other hand,
the distance between Hylotoma and the Gimbicides is
bridged by such genera as Syzygonia and Incalia,
which again are related to Brachytoma, especially
in body form and in the formation of the trophi,
in which the number of joints is reduced, thereby
approximating with the Siricidce. In these tribes we
find spined tibiaa, as in Lyda, and appendicular cellules
in the forewings, neither of which exist with the Tenthre-
dina. Besides that, Lophyrus, Gimbex, and Hylotoma
agree with Lyda and the Siricidce in the form of the
metathorax. The only partial exception to this is
Honoctenus, which, however, differs from Gladius in the
form of the antennae, and in its larva having twenty-
two legs.

I would then divide the family in the first place
into two divisions : division 1 containing the Tenth-
redina, Nematina, Hylotomina, Cimbicina, and Lophy-
rina, all distinguished by the larvae having six or more



CLASSIFICATION. 65

ventral legs ; the second division will include the
Lydina, distinguished, iittrr <t!i<>, by the larvae wanting
abdominal legs. The first section I would arrange
in two series. On the one hand, Tenihredina and
Nematina a homogeneous section, on the other Ciiiilx'-
ciiidy Hylotomina, and Lophyrina, three sharply cut off
groups, but having more connecting links between
themselves than with either T>'nf//rr.Jntn or Nemati,/".
This arrangement may be tabulated as follows :

I. Larvae with ventral legs. Prothorax emarginate behind. Middle

lobe of mesonotum much longer than broad, not separated
from scutellum by a deep fovea. Basal nervure not received
in first cubital cellule.

A. Fore lobes of metanotum well developed, so that the cenchri

are separated from the scutellum by a comparatively wide
space.

1. Larvae with twenty-two legs. Fore wings with two

radial cellules. Second and third cubital cellules
receiving each a recurrent nervure. Lanceolate
cellule rarely petiolate. Antennae usually 9-jointed,
rarely 7 15. Tenihredina.

2. Larvae with twenty legs. Fore wings with one, rarely

with two radial cellules. Second (or first when there
are only three) receiving both recurrent nervures.
Lanceolate cellule petiolate, rarely constricted. An-
tennae 9-jointed. Nematina.

B. Fore lobes of metathorax not well developed, cenchri almost

touching scutellum.

1. Antennae clavate. Sides of abdomen acute. Larvae

with twenty-two legs, ejecting an acid liquid from
lateral pores. Cimbicina.

2. Antennae 3-jointed. Fore wings with one radial cellule,

usually appendiculate. Tibiae spined. Larvae with
eighteen to twenty legs. Hylotomina.

3. Antennae multiarticnlate, serrate in ? , flabellate in d" .

Larvae with twenty- two legs. Lopliyrina*

II. Larvae without ventral legs. Basal nervure received in the first

cubital cellule. Middle lobe of mesonotum not much longer
than broad, and separated from the scutellum by a deep
fovea. Pronotum subtruncate at its hind margin. Tibiae
spined.

Antennae setaceous, multiarticulate. Abdomen depressed. Tere-
bra not exserted. Lydina.

Antennae 12-jointed, the third very much larger than any of the
others. Terebra exserted. Pinicolina.

* Blasticotoma, Kl. (not a British insect), will form another division
of this section, distinguished by its exserted ovipositor, 4-jointed



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