April, '14] MCCOLLOCH: CHINCH BUG PARASITE 219 



was causing so much damage that he secured no income from his 

 investment, and finally sold the property at a loss. 



President P. J. Parrott: The next paper, entitled "Notes on the 

 Life History, Distribution and Efficiency of the Egg Parasite of the 

 Chinch Bug," will he presented by Mr. J. W. McCuUoch. 



A PARASITE OF THE CHINCH BUG EGG 



By James W. McColloch, Assistant Entomologist, and H. Yuasa, Student Assistant, 



Kansas State Agricultural College 



Introduction 



Probably very few insects have received the attention from ento- 

 mologists that the chinch bug has. Without a doubt the chinch bug 

 is the most serious pest with which the farmers of the grain belt have 

 to contend, and the amount of damage done by it in the last 

 sixty years reaches into the hundreds of millions of dollars. Every 

 experiment station in the area mentioned has at some time carried on 

 investigations relative to the chinch bug, and it has been thought 

 that the life history and economy of this insect was well understood. 



Of all the staple crop insects, the chinch bug has been the only 

 one for which there is no insect parasite. Prof, F. M. Webster^ says 

 ''there may sometimes appear hymenopterous parasites of the eggs, 

 but we have as yet no proof of the existence of such in this country, 

 and only suspect the possibility of such a phenomenon because other 

 allied species have similar enemies, which destroy their eggs." In 

 April, 1913, the writers collected chinch bug eggs in the field which 

 bore signs of parasitism, and later parasites were bred from these 

 eggs which Mr. A. B. Gahan, entomological assistant, United States 

 Bureau of Entomology, has described under the name Eumicrosoma 

 benefica. 



History of Discovery 



In the course of a series of experiments conducted by the department 

 of entomology of the Kansas State Agricultural College on the life 

 history of the chinch bug, a large number of eggs were collected 

 in the field to determine the first appearance of young bugs and the 

 mortality of the eggs. The eggs, which were collected at different 

 intervals and in different locahties, were examined daily. While 

 thus examining the eggs it was noticed that some of them were becoming 

 dark in color instead of assuming the usual red coloring. These eggs 

 were isolated and on May 19 there emerged from them three parasites. 



1 Bui. 69, U. S. Bur. of Ent. 



