List of the Insect Fauna of the County. 



135 



the young shoots and leaf- 

 petioles ; it is mature in 

 summer, and the gall-fly 

 emerges therefrom in Au- 

 gust to October. Andricus 

 NODULi, Hartig. (Fig. 21). 



QuERcusEoBUR,L. Bud. 

 The smooth, spherical, 

 hard, yellowish brown, bul- 

 let gall of C. KoUari is now 

 well known everywhere. It 

 is dark or yellowish green 

 when fresh, and occurs on 

 the terminal and axillar 

 buds of the young twigs 

 often in clusters of three 

 or four together. In section 

 the gall, which varies from 

 one -half to an inch in dia- 

 meter, shows a thick, loose- 

 celled parenchyma with a 

 radiate appearance sur- 

 rounding one hard-walled, 

 small, round larva-cell. The 

 galls mature in autumn, 

 and the gall-flies emerge 

 therefrom in September 

 and October, and through- 

 out the following spring ; 

 the galls do not fall from 

 the twigs upon the emerg- 

 ence of the tenants, but 

 frequently persist even for 

 years. Cynips Kollari, 

 Hartig. (Fig. 22). 



QuERcusRoBUR,L. Bud. 

 The artichoke gall of the 

 oak is about the size of a 



Fig. 21. Andricus nodvli. 



Fig. 22. Cynips Kollari. 



