Cynips Kollari. 165 



C aries Gir. ; C lignicola Htg. ; C. tindoria ; C caliciformis 

 and C galeata, Gir. : species only to be distinguished from 

 each other by their galls. 



Rearing the fly. The mature galls are collected in 

 September or October, about which time the fly will be 

 found lying with its head towards the equator of the gall in 

 the direction of most easy exit. Where the gall is double, it 

 occasionally happens that a fly gnaws its way into the twin 

 gall. The flies emerge during September and October, live 

 about a month, and prick the buds, laying about 800 eggs. 

 Some flies winter in the galls, and emerge from the end 

 of April to the beginning of June. The large double galls 

 with one larva chamber usually afford only one small gall- 

 maker. If the larvae be removed from the galls in August, 

 after the nutritive tissue of the gall has been consumed, the}'' 

 will be found to complete their development in small pill- 

 boxes, as perfectly as if they had been left in the galls. The 

 parasites and inquilines as a rule emerge in the spring. 



Experimental breeding. In 1857 Mr. F. Smith of the 

 British Museum had a bushel and a half of the galls from 

 Devonshire ; the flies from these began to emerge in April, 

 and continued to do so till the end of Ma}'. He obtained 

 i2,QOO examples, all of which were female. He placed 

 sixty galls in separate boxes, and, as soon as the flies came 

 out, he carried the boxes to diflerent localities in the vicinity 

 of London, and placed them on low oak scrub. He revisited 

 the localities in August, and found galls on the same trees in 

 eight cases out of twelve, but no galls on any other trees in 

 their neighbourhood. From these galls he again obtained 

 the same Cynips and once more placed it in isolated situations, 

 with the result that galls were again obtained in the same 

 proportion as before. In no case could there have been, he 

 says, ' any connexion with the male sex, unless that sex be 

 of microscopic dimensions \' 



In the autumn of 1881, Beyerinck enclosed a number of 

 flies in nets of muslin, strained on wire frames, and these 



1 Zoologist 7332, quoted also in The Entotnologist, vol. vii. p. 251 ; 

 1874. 



