Andricus injiator. 43 



8^. Andricus inflator. Htg/ 



Gall. This gall Is developed from a bud, is of 

 a green colour, and has a foliaceous covering. In 

 appearance it resembles an enormously thickened and 

 shortened shoot. In the first year growth is not per- 

 ceptibly interfered with, and the winter buds are formed 

 in the ordinary manner above the gall in the axils of 

 the leaves. Next year, however, all these shoots die 

 away. A longitudinal section exhibits a cylindrical 

 cavity within the gall, at the lower end of which there 

 is a little inner gall-chamber from which the fly proceeds. 

 The upper end of the cavity is closed by a covering 

 which is at first red and later of a yellowish colour. 

 (Fig. 8^) 



To collect the flies the galls must be gathered in the 

 middle of June. The flies emerge at the end of June 

 or beginning of July. 



!Fly. Size 2-4 mm. Head and thorax black, slightly 

 shining ; abdomen in the female black above, red or 

 orange beneath ; in the male, entirely black ; legs 

 orange, but the posterior tibiae and coxae dark ; 

 antennae dark, pale at the base. 



Experimental breeding. The females as soon as 

 they emerge and have been fecundated seek out the 

 most tender buds, either terminal or axillary, and lay 

 one t^g in each bud. Sometimes the flies also prick 

 those axillary buds which have been formed on the gall, 

 and from these pricked buds the Aphilotrix globuli galls 

 develop in September. In this way the singular fact 



[* Andncus globuli, sexual form, Cameron. Cynips inflator, Thorns.] 



