Guide to the study of insects, and a treatise on those injurious and beneficial to crops: for the use of colleges, farm-schools, and agriculturists online

male." (Osten Sacken.) Siebold supposes in such cases that
there is a true parthenogenesis, which accounts for the immense
number of females.

JJuron Osten Sacken. however, thinks that these females are
impregnated by males of the same species which are produced
from a different sort of gall, existing, however, on the same
species of tree. He reports in the Proceedings of the Acad-
emy of Natural Sciences of Philadelphia, July 1861, "an
observation, which, if confirmed, would solve the question of
the sexes of Oynipidsi 1 . From a singular, spindle-shaped gall
on the red oak, I reared a male Cynips, which is similar to the
gall-fly, Cynips conflucns Harris, of the common oak-apple of
the red oak, known by the female sex only, and looks exactly
as one might suppose the male Cynips confluens, if known,
ought to look. If it is proved that the Cynips of the spindle-

abdomen of Cynips, showing the relations of segments 7-8, the sternal portion of
the ci-lith segment being obsolete; .<?;>, the single pair of abdominal spiracles; VI,
terminal ventral piece, from which the sheaths (.<? s) and the ovipositor (o) take
their origin: it is strongly attached at m to the tergites of the sixth and seventh
rings; o, ovipositor; s, s its sheaths; a, an appendage to v, the terminal sternite.
Walsh.

U



210 HYMENOPTERA.

shaped gall is the male of the Cynips of the oak-apple, and if
it is shown, by further observation, that in the genera, supposed
to be agamous, by Hartig, the males produced from galls are
different from those of the females, then it will be plain how
28,000 galls of the same kind could give 10,000 females and
not a single male.

"A strong proof in confirmation of my assertion is, that in
those genera, the males of which are known, both sexes are
obtained from galls in almost equal numbers ; even the males,
not unfrequently, predominate in number (see Hartig, 1. c. iv,
399). Now the gall-flies, reared by me from the oak-apple,
were all females. Dr. Fitch, also, had only females ; and Mr.
B. D. Walsh, at Rock Island, Illinois, reared (from oak-apples
of a different kind) from thirty-five to forty females, without a
single male. This leads to the conclusion that the Cynips of
the oak-apples belongs to the genera hitherto supposed to be
agamous."

For an account of the habits and many other interesting
points in the biolog}^ of these interesting insects, we further
quote Baron Osten Sacken. ' ' Most of the gall-flies always attack
the same kind of oak ; thus, the gall of C. seminator Harris,
is always found on the white oak ; C. tubicola Osten Sacken on
the post oak, etc. Still, some galls of the same form occur on
different oaks ; a gall closely resembling that of C. quercus-
globulus Fitch, of the white oak, occurs also on the post oak,
and the swamp chestnut oak ; a gall very similar to the com-
mon oak-apple of the red oak occurs on the black-jack oak, etc.
Are such galls identical, that is, are they produced by a gall-fly
of the same kind? I have not been able to investigate this
question sufficiently. Again, if the same gall-fly attacks dif-
ferent oaks, may it not, in some cases, produce a slightly differ-
ent gall ? It w r ill be seen below, that C. quercus-futilis, from a
leaf-gall on the white oak, is very like C. quercus-papillata from
a leaf-gall on the swamp-chestnut oak. I could not perceive
any difference, except a very slight one in the coloring of the
feet. Both gall-flies may belong to the same species, and
although the galls are somewhat different, they are in some
respects analogous, and might be the produce of the same gall-
fly on two different trees.



CYNIPID^E. 211

"Some gall-flics appear very early in the season ; Cynips
quercus-palustris for instance, emerges from its gall before the
end of May ; these galls are the earliest of the season ; they
grow out of the buds and appear full grown before the leaves
are developed. May not this gall-fly have a second generation,
and if it has, may not the gall of this second generation be
different from the first produced, as it would be under different
circumstances, in a more advanced season, perhaps on leaves
instead of buds, etc?

"A remarkable fact is the extreme resemblance of some of
the parasitical gall-flies with the true gall-fly of the same gall.
Thus, Cynips quercus-futilis, O. Sacken, is strikingly like Aulax?
futilis, the parasite of its gall. The common gall on the black-
berry stems produces two gall-flies which can hardly be told
apart at first glance, although they belong to different genera."
(Proceedings of the Entomological Society of Philadelphia.)

Hartig has divided this family into three sections : First,
Cynips and its allies, the true gall-flies (Psenides) in which the
second (counting the slender pedicel as the first) segment of
the abdomen is longer than half its length, and the subcostal
area is narrow, the basal areolet (cell) being opposite the base
of the former.

Cynips confluens Harris forms the oak-apple commonly met
with on the scrub-oak. There is a spring and summer brood.
These galls, sometimes two inches in diameter, are green and
pulpy at first, but when ripe have a hard shell with a spongy
interior, in the centre of which, lodged in a woody kernel,
which serves as a cocoon, the larva transforms, escaping
through a hole, which it gnaws through both the kernel and
shell. We have found the fly ready to escape in June, and Dr.
Harris has found it in October. Two galls are represented on
Plate 4, fig. 13 ; the larger of which has been tenanted, after
the gall-flies had escaped, by an Odynerus. Cynips gallce-tinc-
torice Olivier produces the galls of commerce, brought from
Asia Minor.

Biorhiza (Apophyllus Hartig) is a wingless genus, and lives
beneath the earth in galls formed at the roots of oak trees.
Biorldza nigra Fitch is black throughout, including the antennaB
and feet, and is but .08 inch long.



212 HTMENOPTERA .

Galls are often found on the blackberry, tenanted by another
genus, Diastroplius, which has usually fifteen-jointed antennae
in the male, and one joint less in the female. On opening a
gall containing this fly, we often find an inquiline gall-fly,
Aulax, "showing the most striking resemblance in size, color-
ing and sculpture, to the Diastrophus, their companion. The
one is the very counterpart of the other, hardly showing any
differences, except the strictly generic characters." (Osten
Sacken.) These galls are also infested by Chalcid parasites,
Callimome (two species), Ormyrus, and Eurytoma.

Osten Sacken enumerates "eight cjmipidous galls on the dif-
ferent kinds of roses of this country." The flies all belong to
the genus Rliodites, which is distinguished by the under side
of the last abdominal segment being drawn out into a long
point, while the antennae are fourteen-jointed
in both sexes. 72. rosce produces the bede-
guar gall ("from the Hebrew bedeguacli, said
to mean rose- apple"). It was formerly used
as a medicine. The galls form a moss-like
mass, encircling the rose branch. JKhodites
Fig. us. dichlocerus of Harris (Fig. 143), produces

hard, woody, irregular swellings of the branches.

We now come to the second section, the Guest gall-flies (In-
quilinae), which are unable to produce galls themselves, as they
do not secrete the gall-producing poison, though possessing
a well developed ovipositor. Hence, like the Nomada, etc.,
among bees, they are Cuckoo-flies, laying their eggs in galls
already formed.

This group may generally, according to Mr. Walsh, be dis-
tinguished from the preceding by the sheaths of the ovipositor
always projecting, more or less, beyond the "dorsal valve,"
which is a small, hairy tubercle at the top of the seventh ab-
dominal segment. This dorsal valve also projects greatly.
In almost all the species, the ovipositor projects from between
the tips of the sheaths.

Among the Inquiline genera are Synoplirus, Amblynotus,
Synerges, and Aulax, which are guests of various species of
Cynipides.

In Figites and allies (Figitidse), the third section of the




TENTHREDINIMJ.



213



family, the second segment is shorter than half the length of
the abdomen, being much longer and less high and compressed
than in the Cynipides, and the ovipositor is retracted within
the abdomen. These insects are true internal parasites, re-
sembling the Chalcids. Ibalia is a parasite on a wood-beetle.
This genus has, by Walsh, been placed in the Cynipides.
Figites has feather-like antennae in the male ; it is a parasite
on the larvae of Sarcophaga. The genus Allotria is a para-
site on Aphis.

Walsh states that two genera, which he has identified as
Kleidotoma and Eucoila are true Figitidce, and u have the
wings fringed like a My mar ^ and the former has them emargi-
nate at tip with the radial area in my species distinctly open,
and the latter simple at tip with the radial area in my species
marginally closed by a coarse brown vein." Eucoila is sup^
posed to be parasitic on some insect attacking the turnip.

TENTHREDINID^E Leach. The Saw-flies connect the Hymen-
optera with the Lepidoptera. In the perfect state they con-
form to the Hymenop- ^ a

terous type, but as b

larvae they would often
be mistaken for Lepi-
dopterous larvae, and
in their habits closely
resemble many cater-
pillars. The three
divisions of the body,
usually so trenchantly
marked in the higher
Hymenoptera, are here
less distinct, since the abdomen is sessile, its basal ring being
broad and applied closely to the thorax, while the succeeding
rings are very equal in size. The head is broad and the thorax
wide, closely resembling that of the Lepidoptera. The wiurs
(Fig. 144, fore- wing) are larger in proportion to the rest
of the body than usual; they are more net- veined, the cells
being more numerous and extending to the outer margin.*

*In treating of this family we avail ourselves largely of the important work on
the American species, publishing at the time of writing, by Mr. E. Norton, in the
Transactions of the American Entomological Society, vols. 1, 2. We therefore




214 HYMENOPTEKA.

All these characters show that the saw-fly is a degraded
Hymenopter.

The antennae are not elbowed ; are rather short and simple,
clavate, but in rare instances fissured or feathered. The ab-
domen consists, usually, of eight external segments, the two
last being aborted on the under side, owing to the great develop-
ment of the ovipositor. The ovipositor or "saw" (compare
Fig. 24) consists of two lamellae, the lower edge of which is
toothed and fits in a groove in the under side of the upper one,
which is toothed above, both protected by the usual sheath-like
stylets. On pressing, says Lacaze-Duthiers, the end of the
abdomen, we see the saw depressed, leave the direction of
the axis of the body, and become perpendicular. By this
movement the saw, which both cuts and pierces, makes a gash
in the soft part of the leaf where it deposits its eggs.

The eggs are laid more commonly near the ribs of the leaf,
in a series of slits, each slit containing but a single egg.
"Some species, on the other hand, introduce their eggs by
means of their saws into the edges of leaves (Nematus conju-
gatus Dahlb.), and others beneath the longitudinal ribs of the
leaves. A few, indeed, merely fasten their eggs upon the outer
surface of the leaves (Nematus grossularice, etc.), attaching them
together like a string of beads (Reaumur, vol. v, plate 10, fig.
8), whilst a few place them in a mass on the surface of the leaf
(ibid, plate 11, figs. 8, 9)." (Westwood.) The irritation set up
by the saws in the wounded leaf, causes a flow of sap which is
stated by Westwood to be imbibed by the egg, so that it swells
gradually to twice its original size. It is known that the egg
of ants increase in size as the embryo develops, and we would

copy his diagram (Fig. 144), showing the venation of the wing (compare Fig. 29
and our nomenclature), with the explanation of parts given by him.

a, stigma; b, costa or costal margin; c, apical margin; d, costal and post-
costal veins ; e, externomedial ; /, #, anal ; /*, posterior margin ; i, marginal vein ;
j, submarginal vein; fc, first, second, and third (transverse) submarginal nervures;
I, recurrent nervui'es (discoidal); m, discoidal vein; ?i, first and second inner api-
cal or submarginal nervures. Bullae or clear spots, on the veins or nervures, with
bullar or clear lines crossing them. 1,2, marginal or radial cells ; 3, 4, 5, 6, submar-
ginal or cubital cells; 7, 8, 9, discoidal cells; 10, costal cell; 11, 12, brachial or me-
dial cells ; 13, 14, inner and outer apical cells. (Hinder cells, Hai-tig. Cellule du
limbe, St. Farg.) No. 11 is sometimes the medial, and Nos. 12 and 13 the submedial
cells; Nos. 9 and 14 the apical cells; Nos. 7 and 13 discoidal; Nos. 10, 11, 12, 15, the
first, second, third and fourth brachial cells; 15, lanceolate cell. 1, open; 2, con-
tracted; 3, petiolate; 4, subcontracted; 5, with oblique cross nervure; 6, with
straight cross nervure.



TENTHREDINID^. 215

question whether the increase in size of the eggs of the Saw-
fly is not rather due to the same cause.

The punctures in the plant often lead, in some genera, to the
production of galls, in which the larvae live, thus showing
the near relationship of this family to the gall-flies (Cynipidae).

The larvae -strongly resemble caterpillars, but there are six
to eight pairs of abdominal legs, whereas the caterpillar has
but five pairs. Many species curl the hind body up spirally
when feeding or at rest. They are usually green, with lines
and markings of various colors. They usually moult four
times, the last change being the most marked. Most of the
larvae secrete silk and spin a tough cocoon, in which they hiber-
nate in the larva, and often in the pupa state. The pupa has
free limbs, as in the other families. The eggs are usually de-
posited in the leaves of plants, but in a few cases, according
to Norton, in slender or hollow stems. While some are slug-
shaped, like the Fear-slug, others like Lyda inanita, mentioned
by Westwood, live on rose bushes, and construct- a " portable
case, formed of bits of rose-leaves arranged in a spiral coil;"
and other species are leaf-rollers, like the Tortricids. The
larva of Ceplius does injury to grain, in Europe, by boring
within the stems of wheat. A remarkable instance of the care
of the saw-fly for her young, is recorded by Mr. R. H. Lewis,
who observed in Australia, the female of Perga Lewisii deposit
its eggs in a slit next the midribs of an Eucalyptus leaf. They
were placed transversely in a double series. "On this leaf
the mother sits till the exclusion of the larvae ; and as soon as
these are hatched, the parent follows them, sitting with out-
stretched legs over her brood, protecting them from the attacks
of parasites and other enemies with admirable perseverance."
(Westwood.)

The species are mostly limited to the temperate zone, but
few being found in the tropics. The perfect insects mostly
occur in the early summer, and are found on the leaves of the
trees they infest, or feeding on flowers, especially those of
the umbelliferous plants.

The genus -Cimbex contains our largest species, the antennae
ending in a knob. C. Americana Leach is widely distributed,
and varies greatly in color. The large whitish larva, with a



216 HYMENOPTERA.

blackish dorsal stripe, may be found rolled up in a spiral on
the leaves of the elm, birch, linden and willow trees. When
disturbed it ejects a fluid from pores situated above the spira-
cles. It constructs a large tough parchment-like cocoon, and
the fly appears in the early summer.

The genus Trichiosoma is recognized by its hairy body, and
the antennae have five joints preceding the three-jointed club.
T. triangulum Kirby is found in British America and Colorado,
and a variety, T. bicolor Harris, on Mount Washington ; it is
black, except the tip of the abdomen, with the fourth and fifth
joints of the antennae piceous, and the thorax is covered with
ash-colored hair.

In Abia the antennae are seven-jointed, with the club obtuse ;
the body is villose, the abdomen having a metallic silken hue.
The Abia caprifolium Norton (Fig. 145, larva) is very destruc-
tive to the Tartarian Honeysuckle, sometimes stripping the
bush of its leaves during successive sea-
sons in Maine and Massachusetts. It
hatches out and begins its ravages very
soon after the leaves are out, eating cir-
cular holes in them. It lies curled up
on the leaf and when disturbed emits
drops of a watery fluid from the pores in
the sides of the body, and then falls to
the ground. During the early part of
August it spins a pale yellowish silken
cocoon, but does not change to a pupa,
Mr. Riley states, until the following
Fig. 145. spring. He describes the larva as being

common about Chicago ; that it is "bluish green on the back,
and yellow on the sides, which are pale near the spiracles, and
covered with small black dots. Between every segment is a
small, transverse, yellow band, with a black spot in the middle
and at each end. Head free, of a brownish black above and
color of the body beneath." The fly is described by Norton
as being black, with faint greenish reflections on the abdomen ;
there are two white bands at the base of the metathorax, and
the wings are banded. It is .36 inch long and the wings ex-
pand .70 inch. The larvae can easily be destroyed from their




TENTHREDINID^E. 217

habit of falling to the ground when the bush is shaken, where
they can be crushed by the foot. Dr. Fitch has reared Abia
ccntfii from one or two cocoons found on the wild cherry, the.
fly appearing in New York during March.

Hylotoma is a much smaller genus ; the basal joint of the
antenna is oval, while the second is small and round, and
the terminal joint is very long. The larva is twenty-footed, and
when eating curves the end of the body into the form of an S.
The pupa is protected by a gauzy, doubly enveloping cocoon.
II. McLeayi Leach is wholly black, sometimes with a tinge of
blue. It is found throughout the Northern States.

The genus Pristipliora, closely allied to Nematus, is known
by its nine-jointed antennae, and the single costal cell ; the first
submarginal (subcostal) cell having two recurrent veinlets.
P. identidem Norton has been discovered by Mr. W. C. Fish to
be destructive to the cranberry on Cape Cod. He has reared
the insect, and sent me the following notes on its habits, while
the adult fly has been identified by Mr. Norton, to whom I
submitted specimens. The larvae were detected in the first
week of June, eating the leaves ; "they were light or pale yel-
lowish green when first hatched," and grew darker with age.
The head of the young was dark, but in the full-grown worm
lighter. When full-grown they were about .30 of an inch in
length, and had two lighter whitish green stripes running along
the back from head to tail. They had spun their cocoons by the
20th of June in the rubbish at the bottom of the rearing bot-
tles. On the 29th of June they came out in the perfect state.
AVe would add to this description that the body, in two alco-
holic specimens of the larvae, was long, cylindrical, and smooth,
with seven pairs of abdominal feet. The head is full, rounded
and blackish, but after the last moult pale honey-yellow. The
male is shining black, and Mr. Norton informs me that it is
his P. idioto. P. grossularice Walsh is a widely diffused species
in the Northern and Western States, and injures the currant
and gooseberry. The female fly is shining black, while the
lu-ad is dull yellow, and the legs are honey-yellow, with the tips
of the six tarsi, and sometimes the extreme tips of the hinder
til.ia- and of the tarsal joints pale dusky for a quarter of their
length. The wings are partially hyaline, with black veins, a



218 HYMENOPTEKA .

honey-yellow costa, and a dusky stigma, edged with honey-
yellow. The male differs a little in having black eoxse. Mr.
Walsh states that the larva is a pale grass-green worm, half
an inch long, with a black head, which becomes green after
the last moult, but with a lateral brown stripe meeting with
the opposite one on the top of the head, where it is more or
less confluent ; and a central brown-black spot on its face.
It appears the last of June and early in July, and a second
brood in August. They spin their cocoons on the bushes on
which they feed, and the fly appears in two or three weeks, the
specimens reared by him flying on the 26th of August. P.
sycoplianta Walsh is an " inquiline," or guest gall-saw-fry,
inhabiting a Cecidomyian gall on a willow.

The genus Euura comprises several gall-making species. ' It
differs from the preceding genus in the second, instead of the
first, submarginal cell having two recurrent venules. Mr.
Walsh has raised E. orbitalis Norton (E. genuina Walsh) from
galls found on Salix humilis. This gall is a bud which is
found enlarged two or three times its natural size, before it
unfolds in spring. The larva is twenty-footed, is from .13 to
.19 of an inch long, of a greenish white color, and the
head is dusky. It bores out of its gall in autumn, descending
an inch into the ground, where it spins a thin, silken, whitish
cocoon. The gall of E. salicis-ovum Walsh is found on Salix
cordata. The female is shining yellow, while the ground color
of the male is greenish white. The gall of this species is an
oval roundish, sessile, one-chambered, green or brownish swell-
ing, .30 to .50 of an inch long, placed lengthwise on the side of
small twigs. The larva is pale yellowish, and the fly appears
in April. The fly is, according to Walsh, " absolutely undistin-
guishable by any reliable character from the guest gall-saw-fry,
Euura perturbans Walsh," which inhabits dipterous galls made
\)j Cecidomyian flies on the willow and grape (Walsh) . If these
two " species" do not differ from each other, either in the larva
or adult state, "by any reliable characters," then one must
question whether the variation in habits is sufficient to separate
them as species, and whether E. salicis-ovum does not, some-
times, instead of forming a new gall, lay its eggs in a gall ready-
made by a dipterous gall-fly. We have seen that Odyiierus



TENTHKEDINIDuE. 219

albophaleratus, which usually makes a mud cell situated in the
most diverse places, in one case at least, makes no cell at all,
but uses the tunnel bored out by a Ceratina ! and yet we should
not split this species into two, on account of this difference
in its habits. We had written this before meeting with Mr.
Norton's remark that "it is difficult to give a hearty assent
to Mr. Walsh's inquilines or guest-flies, without further inves-
tii>;ition." (Transactions of the American Entomological
Society, vol. i, p. 194.)

In Nematns the nine-jointed antennae have the third joint
longest. There is one costal and four subcostal cells, the
second cell receiving two recurrent veinlets ; the basal half
of the lanceolate cell is closed ; the hind wings have two mid-
dle cells, and the tibiae are simple.

The larvae are hairy with warts behind the abdominal feet.
The}- have twenty feet, the fourth and eleventh segments (count-
ing the head as one) being footless. They are either solitary,
feeding upon the leaves of plants, or social and generally found
on pine trees, while some species live in the galls of plants. The
pupa, according to Hartig, is enclosed in an egg-shaped cocoon,
like that of Lophyrus, but less firm, though with more outside
silk. It is generally made in the earth, or in leaves which fall
to the ground. N. vertebratus Say is green, with the antennaB
and dorsal spots blackish, the thorax being trilineate. There
are fifty species in this country, of which the most injurious
one, the Gooseberry saw-fly, has been brought from Europe.
This is the JV. voitricosus Klug which was undoubtedly imported
into this country about the year 18GO, spreading mostly from
Rochester, N. Y., where there are extensive nurseries. It does
more injury to the currant and gooseberry than any other native
insect, except the currant moth (Abraxas? tiliaria). Professor
Winchell, who has studied this insect in Ann Arbor, Michigan,
where it has been very destructive, observed the female on
the 16th of June, while depositing her cylindrical, whitish and
transparent eggs, in regular rows along the under side of
tlu- veins of the leaves, at the rate of about one in forty-live
seconds. The embryo escapes from the egg in four da3's.
It feeds, moults and burrows into the ground \vithin a period of