OF EPPING FOREST.
159
Gall.
Situated in the axils of the leaves. Shape: Cylindrical,
pointed at the apex, furnished with conspicuous longitudinal ribs.
It grows on a long thin stalk. Colour: Green; ribs red.
Imago.
Colour; Reddish yellow. Antennae: Dark. Abdomen: Dorsal surface dark
brown. Legs: Brownish yellow, posterior tibiae dark, very like A. quadrilineatus;
some specimens are practically identical, though both are very variable.
(16.) Sexual Generation. VIa. Andricus cirratus (Adler.)
Gall.
Appears on the stalk of the male catkin. Green when
young, becoming yellow and brown with age, furnished with
long white hairs, especially at the apex. I have found specimens
covered with long straggling white hairs, which are not dense,
the galls being yellowish, small and rounded. Three or four galls
may be found together, forming a more or less woolly mass.
Imago.
Colour; Black. Antennae: Testaceous, apices dark. Thorax: Tegulae
entirely, and pronotum partially yellow. Abdomen dark above, sides reddish
yellow, ventral surface reddish brown. Legs: Yellow; posterior trochanters and
bases of coxae dark. Wings; Hyaline.
Account of Generation Cycle.
When the larvae are mature, the A. callidoma galls lose their
colour and become a uniform dull brown. The insects emerge in
April, and lay their eggs on or between the anthers. The
resulting gall, A. cirratus, appears in May, the flies emerging
about the middle of June.
After copulation they proceed to oviposit in the axillary
buds. About the middle of July the galls of A. callidoma appear
from the buds, though in many cases they do not appear until
August.
When mature these galls fall to the ground, the flies appear-
ing either in the following spring or not until April of the second
year.
OCCURRENCE IN EPPING FOREST.
Andricus callidoma. Fairly plentiful. This gall, when
parasitised, may remain on the tree for some time before
falling to the ground; brown and dry galls may often be found
still attached quite late in the year. First appearance noted,
August 21st.