HYMENOPTERA OAK GALLS. 



149 



ember projecting from the bud-scales, and would perhaps measure 

 about ] inch in diameter. I found it very common in Delamere 

 Forest, Cheshire, but have not hatched the fly. 



8a. Andricus inflator (Htg.) 



This gall (fig. 143), which is the alternating species of A. globuli, is 

 originally formed from a bud. In general appearance it is somewhat 

 like the thickened portion of that part of a turnip immediately above 

 the bull) which is finally 

 surmounted by the leaves. 

 The gall proper is really 

 within the woody portion, 

 and during the year in 

 which eggs are deposited 

 growth is not perceptibly 

 interfered with, but the 

 next year the portion 

 affected by the insect 

 agency swells, and the 

 adventitious buds formed 

 thereon give rise to the 

 tuft of leaves referred to. 

 The galls are not very com- 

 mon, but may be looked 

 for in June, and the flies 

 emerge only in July. 



"Fly size 2 to 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 ; antenna dark, pale at the base." Adler. 



The next gall to be considered is very common in the sexual form, 

 but not so general in the agamic stage. The latter is, according to 

 Adler's classification, Aphilothrix collaris (Htg.), and the former, 

 Andricus curvator (Htg.), or the leaf-twisting gall. 



The gall of (9) Aphilothrix collaris is formed upon a bud, and, 

 being concealed, may easily be overlooked. Adler says : " In Sept- 



Fig. 143. Gall of Andricus inflator. 



