88 Observations on Cynipidae. 



deformities, being sometimes deeply indented or dis- 

 torted. If the galls are formed on catkin stems, these 

 are often abnormally thickened and remain on the 

 twigs the whole summer, instead of falling off in the 

 usual way as soon as the flowering is over. The galls 

 appear at the end of May, mature in June, and then 

 fall to the ground. (Fig. 20.) This gall has a strong 

 resemblance to the Aphilotrix callidoma gall, but is 

 easily distinguished from it by its point of origin ; it 

 never grows from a bud like Aphilotrix callidoma. 



The rearing of the Fly is accomplished without 

 difficulty. The galls when collected should be kept 

 for some time on damp sand, they should then pass 

 the winter in the open air, and in the following April 

 the fly will appear. Some galls remain dormant one 

 whole year, and the fly does not emerge until the second 

 year. 



Fly. Size 3-4 mm. long; the colour varies from 

 yellowish brown to dark brown ; the lighter specimens 

 have on the mesothorax four black lines of varying 

 breadth, these lines are usually not sharply defined but 

 somewhat blurred ; in the darker specimens the lines 

 are scarcely recognizable, the back appearing an almost 

 uniform dark brown, with the scutellum light. The 

 sides of the thorax have white hairs, otherwise it is 

 smooth and shining. Abdomen dark brown above, 

 with the ventral aspect lighter. The legs vary in 

 colour from orange to brown, coxae dark, femora and 

 tibiae black on the outside. 



Experimental breeding. I am now enabled to state 

 the mode of propagation of this species with absolute 



