Vol. XXvi] ENTOMOLOGICAL NEWS. 147 



A New Parasite of the Chinch Bug Egg (Hym.). 



By JAMES W. McCoLLOCH, Assistant Entomologist, and H. 



YUASA, Student Assistant, Kansas State Agricultural 



College and Experiment Station. 



During the summer of 1914, the Department of Ento- 

 mology of the Kansas State Agricultural College carried on 

 an extensive investigation of the life history of the chinch 

 bug egg parasite (Eumicrosoma benefica Gahan). In the 

 course of this work between seventy-five thousand and one 

 hundred thousand chinch bug eggs were collected in the field 

 to determine the percentage of parasitism and for use in the 

 life history work. These eggs were collected regularly dur- 

 ing the entire summer and were separated into lots of from 

 ten to fifty and kept in small vials where they were examined 

 daily. On August 4th a small, light greenish, parasite was 

 found in a vial of eggs collected July 27th from crab 

 grass. A careful examination of the eggs in the vial showed 

 that one of them had a small round hole cut in the side of it. 

 This was entirely different from the emergence holes cut by 

 either the chinch bug or Eumicrosoma benefica and left no 

 question as to where this parasite had come from. (Fig i.) 

 The egg from which it emerged was attached to another 

 chinch bug egg from which an Enmicrosoma benefica 

 emerged. (Fig. 2.) On August loth another one of these 

 parasites was bred from a chinch bug egg collected from 

 crab grass on August ist. This collection was made from a 

 different field than the one of July 27th. 



One of the projects under the life history work on Eumi- 

 crosoma benefica was to determine whether it had any host 

 other than the chinch bug egg. Collections were made of all 

 kinds of eggs found in the habitat of the chinch bug and its 

 parasites. In these collections large numbers of eggs, which 

 were thought to be eggs of a leaf-hopper, were taken and in 

 nearly every case they were parasitized by this same greenish 

 parasite. The exit hole in these eggs was the same as that in 

 the chinch bug egg. (Fig. 3.) 



