50 BRITISH OAK GALLS. 



Andricus aestivalis, Giraud. 

 (Plate Y, diY. A.) 



Andricus cVstivaJis, Mayr, Cameron, Moslev. 



English name of gall. — " The Cup Grali" 



Position of gall. — On stamiuate catkins of Q. cerris. 



Manner of growth. — Sessile, glabrous, gregarious, conglomerate. 



Colours. — Pale green, greenisli-yello\\% Ijrown. 



Average dimensions of a mature specimen. — Height, 

 10 mm. ; l:»readth, 8 mm. 



May be sought during the months of May to July. 



Growth is complete l)y the end of June. 



The typical condition of the gall is bilocular, but unilarval. 



The larva pixpates in the gall. The imago emerges during 

 June and Jul v. 



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 aiitliors' 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 being found in Britain. It is so distinctive that no 

 collector could fail to identify it. Probably it may be 

 discovered, especially as A. glandinm 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 



