50 BRITISH OAK GALLS. 
Andricus estivalis, Giraud. 
(Plate V, div. A.) 
Andricus xstivalis, Mayr, Cameron, Mosley. 
English name of gall.— The Cup Gall.” 
Position of gall.—On staminate catkins of Q. cerris. 
Manner of growth.—Sessile, glabrous, gregarious, conglomerate. 
Colours.—Pale green, greenish-yellow, brown. 
Average dimensions of a mature specimen.—Height, 
10 mm.; breadth, 8 mm. ‘ 
May be sought during the months of May to July. 
Growth is complete by the end of June. 
The typical condition of the gall is bilocular, but unilarval. 
The larva pupates in the gall. The imago emerges during 
June and July. 
Parasites, Nos. 14, 24, 180. Inquilines, Nos. 3,4. (These 
figures correspond with those in the list at end of volume, where the 
names of the insects and their authors’ names are given in full.) 
This gall appears to have escaped the notice of 
British collectors. I am not aware of any record of 
it bemg found in Britain. It is so distinctive that no 
collector could fail to identify it. Probably it may be 
discovered, especially as A. glandium has been found 
in acorns of the same oak (see p. 59). 
Cameron captured a female insect at Loch Lomond, 
which agreed with a type sent him by Professor Mayr 
(‘ Brit. Phyto. Hymen.,’ vol. iv, p. 107). He does not 
state, however, if he found any of the galls. 
The galls occur in numbers of 20-40, conglomerated 
on the catkin stalk, and while growing somewhat 
resemble a mulberry. The size of the clusters varies 
considerably. Some measure 35 mm. in length and 
75 mm. in girth. They are more or less pressed into 
one another at the point of attachment to the catkin 
stalk by reason of their number, but they are quite 
free from each other at their distal extremity. The 
stalk becomes twisted and thickened. 
A single gall is about 10 mm. high, 8 mm. in breadth, 
pointed at the base, and opening out at the top into a 
cup shape. It consists of two parts, an outer case and 
