LIBRARY

648 COLLEGE ENTOMOLOGY
Family CYNIPIDlE (Haliday 1840) Westwood 1840 (Cy-nip'i-dro; see deriva.
tion supra). Gallwasps, Gallflies, Cynipids.
Minute to small, 1--6 mm., black, brown, or paler in color; smooth and shiny
or partly pubescent. Head small and sometimes defiexed because or the rounded
thorax. Antennre setiform, 11- to 16-segmented. Pronotum fused with mesono­
FIG. 224. Spiny galls of Diplolepis polilus (Ashmead)
of the leaves of wild rose. . A widely distributed
North American gall. (From Insects of Western North
America.)
i
l ,
tum, sides extending to tegulro.
Legs slender; trochanters small
and undivided; posterior claws
simple or bidentate. Wings
absent, rudimentary, or fully
developed; males may be alate
and females apterous or with
vestigial wings; with few veins
and microtrichia; fore pair with
only five closed cells including
the small areolet. Scutellum
and propodeum rarely deeply
sculptured. Abdomen globular
or compressed laterally;
with or without a short petiole;
tergites well chitinized and not
concealing sternites; segment
II enlarged or extending over
posterior tergites; ovipositor
issuing from near middle of
abdomen and coiled within it.
The adults are wasp-like or
ant-like in appearance and
bisexual or agamic or parthenogenetic,
and many have alternate
fall agamic generations.
They appear in the fall or
spring, when the eggs are inserted
in the dormant or developing
buds, leaves, stems,
or roots of the host plants,
resulting in the production of
a great variety of galls on all
parts of the plants including the roots, stems, petioles, leaves, floral parts, or
seeds. The galls or swellings begin to develop soon after the larvre hatch
from the eggs, and it is believed that the proliferation is caused by the larvre.
The character of the galls is determined by the insect rather than by the
plant, and each species produces one or more characteristic kinds of galls.
According to Kinsey, about 86 per cent of all cynipid galls are produced on
Quercus, 7 per cent on Rosa, and 7 per cent on COMPOSIT lEo A few spe-