OF EPPING FOREST. 163
white felt, or lump of cotton wool. The size depends upon the
number of galls collected together.
Imago.
Colour: Reddish yellow, shining. Antennae: Entirely yellow. Thorax:
Mesonotum finely punctured and dull. Abdomen: Darker on the dorsal
surface in the male than in the female, in the latter it is more or less brownish.
Legs: Uniformly yellow.
Account of Generation Cycle.
The insects emerge from the A. autumnalis galls in April, and
oviposit either in the flower or leaf buds, laying a number of eggs
in each bud. According to Adler, flower buds are usually
selected because they mature earlier. About the middle of July
the sexual generations appears from these galls, and the eggs
are laid in the axillary buds. In October the A. autumnalis galls
appear; these mature at the end of the month, and fall to the
ground, the fly appearing in April of the second year,
OCCURRENCE IN EPPING FOREST.
Andricus autumnalis. Not very common. I was only able to
find a few specimens of this gall. First appearance noted,
September 30th.
Andricus ramuli. Not plentiful. These galls, as a rule, were
solitary, and appeared on the catkin more frequently than from
the leaf buds, but I occasionally found two or three matted
together into one formation. The thick felt-like covering
becomes reddish-brown with age. First appearance noted,
May 26th.
(20.) Agamic Generation. X. Andricus ostreus (Htg.)
Inquilines. Synergus tseheki (Mayr) and S. tristis (Mayr).
Gall.
Appears from the veins on the underside of the leaf. It is
covered at the sides when young by two scale-like pieces which
give it the popular name of "the oyster gall." Colour: Yellowish,
usually with reddish spots when young, sometimes entirely red,
yellowish brown when old. Shape: Usually oval, but sometimes
globular.
Imago.
Colour: Brownish black, sometimes quite black. Antennas: Dark, thickening
towards the apex, paler at the base. Thorax: Keels on the median segment
very pronounced and curved. May be streaked with dark rufous. Usually
slightly and finely pubescent. Abdomen: Shining. Legs: Reddish, becoming
darker towards the base. Wings: Somewhat clouded.