162
THE OAK GALLS AND GALL INSECTS
the sexual generation appearing from them at about the
beginning of June. These insects oviposit in the axillary buds.
In September, or not until October in some cases, the A. malpighii
galls are formed. The full grown larva, however, does not
pupate until the following autumn, emerging in April of the
second year. That is to say, the larva in an A. malpighii gall
formed in the autumn of 1898 would not emerge as a perfect insect
until April, 1900.
OCCURRENCE IN EPPING FOREST.
Andricus malpighii. Not common. I found some of these
galls appearing from buds of twigs growing adventitiously on the
trunk of the tree. They appear much later than is the case with
the A. callidoma galls. First appearance noted, September 19th.
I was not able to obtain any Andricus nudus galls in Epping
Forest.
(19). Agamic Generation. IX. Andricus autumnalis
(Htg.)
Inquilines. Synergus nervosus (Htg.), S. apicalis (Htg.)
S. ruficornis (Htg.)
Gall.
Like A. globuli, this gall is formed from the bud its base
being surrounded with bud scales.
The real gall is covered with a brownish green sappy rind
which subsequently falls off. If the gall is not removed, the
rind falls off, but otherwise it remains on the gall, becoming
longitudinally ridged. Shape: Oval, apes pointed. Colour:
Brownish green.
Imago.
Colour: Black. Antennae: Brownish, basal two joints yellowish red.
Thorax: Black, wrinkled and dull. Abdomen: Shining black above, reddish
brown below. Legs: Dark yellowish red, trochanters and bases of coxae
darker.
(19). Sexual Generation. IXa. Andricus ramuli
(Linn.)
Inquilines. Synergus facialis (Htg.) and S. radiatus (Mayr).
Gall.
Develops either from a male flower bud or from a leaf
bud. The gall itself is brownish yellow in colour, covered
thickly with white matted hairs giving it the appearance of