138
The Galls of Essex; a Contribution to a
be not uncommon. The gall is single-celled, and matures
apparently throughout the summer, when the gall-fly emerges
therefrom. Aphilothrix collaris, Hartig (Fig. 27) [agamous
form of Andricus curvator] .
Quercus Robur, L. Bud. This most remarkable gall is
in size and shape much like a barley-corn, but is green in
colour, frequently quartered with red raised stripes, and
occurs on a long, but very thin foot-stalk, though sometimes
Fig. 28. Aphilothrix callidoma.
almost sessile. It is developed from the axillar buds, and is
single-celled ; it matures in summer and autumn; the gall-
fly emerges therefrom in spring. Aphilothrix callidoma,
Hartig (Fig. 28) [agamous form of Andricus cirratus] .
Quercus Robur, L. Bud. This
is the most conspicuous of the bud-
like galls. It occurs on the twigs
of the oak-stubs in the spring, and
is somewhat oviform in shape, of
about the size of an orange pip ; it

is green, purplish or whitish green,
in colour, commonly covered with

Fig. 29.
Aphilothrix albopunctata.
short, whitish, longitudinally placed
spots; its surface is smooth, and it is sessile in the bud, the
bud-scales scarcely showing; there is a well-marked papilla
at the apex.. The gall is single-celled; it falls from the twig
to the ground in May or June, and the gall-fly emerges
therefrom in November. Aphilothrix albopunctata, Schlecht-
endal. (Fig. 29.)