110 IOWA ACADEMY OF SCIENCES. 



Although at tirst it is almost impossible to distinguish stung fruit from 

 external appearances, it becomes very easy after a few days when the apples 

 become gnarly and ill-shapen. 



THE GALL-PRODUCING (;YNIPID^E OF IOWA. 



BY C. P. GILLETTE. 



The Cynipidaj form one of the most interesting, but one of the least 

 studied families of the Hvmenoptera. It is the object of this paper to 

 encourage the collection and study of the gall-pi-oducing Cynipida3 of the 

 State. The species here mentioned have, with one exception (Rhodites mul- 

 tispinosa), been taken by the writer in the past two years in the vicinity of 

 Ames, Iowa. There can be no doubt but what two or three times as many 

 species occur in the State. 



The writer will be glad to receive for study or determination any species 

 that may be sent to him. 



I give with each species mentioned a reference to the original description, 

 a bi-ief description of the gall and the localities from which the species has 

 been taken, so far as known to me. 



LIST OF SPECIES. 



Rhodites multispinosi Gill. Bull. 7, la. Exp. St., p. 284. Entomologica 

 Americana, v. VI., p. 25. 



The galls are abrupt tumor-like excresences from three-fourths of an inch 

 to over an inch in diameter and densely covei'ed with shai'p spines, growing 

 on new shoots of a species of wild rose. Flies issue early in May. Iowa, 

 Minnesota. 



Amiihibolips coccinea O. S., Proc. Eut. Soc. Pha., v. I, p. 243. 



This species produces one of the largest " oak apple " galls that we have. 

 Large galls measure one and three-fourths inches in their greatest diameter, 

 and about a fourth of an inch less in their smallest diameter. Externally 

 there is a thin, smooth, brittle shell; at the center there is an egg-shaped 

 central cell, surrounded by a loose spongy mass, which is easily separated 

 from it; occurring on the leaves of Q. coccinea. Flies emerge about the 20th 

 of June. Michigan, Iowa, D. C. 



Amphibolips cookii Gill. Rep. Mich. B'rd of Agr., 1887, p. 475. Psyche, 

 Vol. V, p. 220. 



The galls are globular and juicy when green, much i-esembling the galls of 

 A. inayiis O. S., and measure from three-eighths to live-eighths of an inch in 

 diamete. The galls are composed of a rather thin outer shell, and central 

 cell held in place by stout radiating fibers. The galls are always found 



