List of the Insect Fauna of the County. 135
the young shoots and leaf-
petioles ; it is mature in
summer, and the gall-fly
emerges therefrom in Au-
gust to October. Andricus
noduli, Hartig. (Fig. 21).
Quercus Robur, L. Bud.
The smooth, spherical,
hard, yellowish brown, bul-
let gall of C. Kollari is now
well known everywhere. It
is dark or yellowish green
when fresh, and occurs on
the terminal and axillar
buds of the young twigs
often in clusters of three
or four together. In section
the gall, which varies from
one-half to an inch in dia-
meter, shows a thick, loose-
celled parenchyma with a
radiate appearance sur-
rounding one hard-walled,
small, round larva-cell. The
galls mature in autumn,
and the gall-flies emerge
therefrom in September
and October, and through-
out the following spring ;
the galls do not fall from
the twigs upon the emerg-
ence of the tenants, but
frequently persist even for
years. Cynips Kollari,
Hartig. (Fig. 22).
Quercus Robur, L. Bud.
The artichoke gall of the
oak is about the size of a
Fig. 21. Andricus noduli.
Fig. 22. Cynips Kollari.