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THE OAK GALLS AND GALL INSECTS
all cases being very much distorted and swollen. This swelling
commenced about the beginning of May. The galls themselves
began to appear at the beginning of June and continued until the
end of August, as I found some fresh galls on the 22nd of the
latter month. Cameron mentions this species as occurring in
Mugdoch Wood and I have also taken it in Kent, but I have
not heard of it from any other locality.
(23.) Agamic Form. XIII. Andricus quadrilineatus-
(Htg.)
Inquiline. Synergus facialis (Htg.).
Gall.
Oval in shape, somewhat flattened at the ends. They may be
smooth, but are usually furrowed. Colour varies between green,
yellow, and red. They are found on the flowering catkin.
Imago.
Very variable. Colour: Usually brownish red. Antennae: Dark, infuscated,
or nearly black. Thorax: Two lines on the median lobe of the mesonotum and
one on the lateral and scutellae foveae, black. A short whitish pubescence is
present on the pleurae and median segment. Scutellum finely rugulose.
Abdomen: Dark brown above. Legs: Brownish yellow, coxae, bases of femora
and outer margin of tibias, dark. Wings: Hyaline, nervures dark brownish.
Cubitus and base of radial cellule, very slightly infuscated.
The A quadrilineatus galls appear in May. The flies emerge
in the following April. They prick the buds of the male catkin
about the middle of April, and the galls are mature at the
beginning of June. In a great many cases the flies do not emerge
until April of the second year.
OCCURRENCE IN EPPING FOREST.
Very abundant. These galls occur in numbers on the
catkins. First appearance noted, May 18th.
(24.) Agamic Form. XIV. Andricus albopunctata
(Schtdl).
Inquilines. Synergus radiatus (Htg.) and S. facialis (Mayr).
Gall.
Grows from a bud, varying a great deal in colour from green
to reddish brown, usually marked with light longitudinal spots. 
In many cases these galls greatly resemble buds; in others,
where the gall grows much larger, they are somewhat similar to
acorns without the cup. They vary in shape, but as a rule
become narrower towards the apex.