4^ Observations on Cynipidae- 



prick for several days. The result was convincing, as 

 in June the little oak was perfectly covered with the 

 galls of Andricus curvator. The illustration was taken 

 from a shoot of this oak. 



[The collared bud gall is found in August or September on Quercus 

 sessiliflora. 



Inquilines. Synergus nervosus and S. palliceps. 



Parasites. Eurytoma vetiicillata and Syiitoinaspis caudatus.^ 



9^. Andricus curvator. Htg.^ 



Gall. The gall forms on the leaves, and appears in 

 May as an irregular thickening of the leaf surface. At 

 first it presents, when cut through, a solid kernel, but 

 as time goes on a cavity is gradually formed, and from 

 its inner wall projects a small brown central gall. If 

 several galls are formed on the same shoot, the 

 leaves are hindered in their development, and remain 

 rudimentary. The flies emerge in June. 



Fly. Size 1-5 to 2 mm. Black. Thorax smooth, 

 sometimes rather rugulose, without sculpture ; abdomen 

 black and shining ; legs testaceous ; coxae always, and 

 femora often, dark. Males and females similar. 



Experimental breeding. I have made many experi- 

 ments with this species. If the fecundated females are 

 placed on an oak sapling, as a rule they soon begin to 

 prick the buds. To do this the fly perches on the point 

 of the bud, and bores its ovipositor obliquely downwards 

 into the interior. Only one egg is laid in each bud, and 

 a long time elapses before any gall formation can be 

 seen. The gall begins to develop in September, but 

 occasionally as early as August. At first the gall is 

 [^ Cynips curvator, Thorns. Andricus perjoliatus, Schenck.] 



