l60 THE OAK GALLS AND GALL INSECTS
Andricus cirratus. Not common. A number of galls may
appear on the same catkin, but often there are only two or three
present. First appearance noted May 18th.
(17.) Agamic Generation. VII. Andricus fecundatrix
(Htg.)
Inquilines. Synergus melanopus (Htg.), S. vulgaris (Htg.)
Gall.
The gall grows from the bud, and somewhat resembles a
hop; it is made up of numerous enlarged scales, which surround
the hard woody inner gall, situated at their base. This inner
gall is usually thrust out, and falls to the ground in late summer,
but this is not always the case. Colour: The true inner gall is
yellowish green; the scales are green, edged with brown, when
young, becoming entirely brown later.
Imago.
Colour: Blackish. Thorax: Covered with white silky hairs with two-
broad stripes towards the outer portion of the parapsidal furrows. These
stripes are smooth and glabrous. The other portions of the thorax are dull and
rugose. Abdomen: Black, shining, somewhat reddish at the sides. Legs:
Usually dark, front tibiae, with strong erect hairs.
(17.) Sexual Generation. VIIa. Andricus pilosus
(Adler.)
These galls which occur on the male catkins, either singly or
many together, are covered with hairs. Colour: Green at first,
becoming brown with age. Shape: Oval, walls thin, apex
prominent.
I was unable to find this gall at Epping Forest.
Imago.
Black in colour, with the thorax smooth and slightly shining, and the
abdomen a dull black. The Antennae are black or brownish black, and the legs
are yellowish.
Account of Generation Cycle.
The insects emerge from the A fecundatrix galls in April. The
ova are laid in the anthers of the catkin, one egg in each anther.
When the male flowers develop in May, the A. pilosus galls
appear in variable numbers, but usually a good many on each
catkin. From these galls the flies emerge in June, and lay one
egg in a bud, many buds being pierced by each insect. Galls