146 THE MONTANA EXPERIMENT STATION 



ENEMIES AND PARASITES. 

 BIRDS 



In some measure the natural enemies of this highly injurious 

 species hold it in check but, as given below, we do not consider them 

 to be the cause for the sudden disappearance of this insect after one 

 year of presence in injurious numbers. Among birds, blackbirds, 

 meadow larks, bluebirds, quail and blue jays have been recorded 

 from Colorado. Professor Wilcox found the blackbird, robin, crow 

 and meadow lark eating the cutworms As would be expected, 

 domestic fowls have learned to eat them also. In this valley we 

 found blackbirds feeding freely on them and bluebirds sparingly. 



i ■■ INSECT PARASITES 



Professor Gillette, of the Colorado Experiment Station, has re- 

 corded two large ichneumon flies as parasitic on CJwriza gratis auxUi- 

 aris, namely, Aviblytclcs subriifiis and Ichneumon longiolus. He also 

 reports having bred one to two thousand specimens of Copidosoma, 

 a genus of the family CJiaJcididae. 



Professor Wilcox found several beetles atacking the larvae ol 

 C. agrcstis, among them being Harpalus and Calosoma. In the infest- 

 ed fields in the Gallatin valley last season we found specimens of 

 Calosoma (species undetermined) feeding on the larvae but not in 

 such numbers as to make much impression on the pest. The most 

 abundant parasite, in our experience with this cutworm, was a Tachi- 

 nid fly, which we have tenatively determined as Pclcteria tcssellata. 

 About five per cent of the caterpillars were infected with the maggots 

 of this species of parasite. 



WILL THIS INSECT AGAIN BE INJURIOUS? 



Farmers have repeatedly asked what became of these insects 

 and what we may expect in the future regarding them. We have 

 been unable to find anyone who has seen any of the caterpillars 

 smce the destructive brood of the spring of 1907 disappeared from 

 sight. 



The immediate disappearance of the species is easily explained. 

 When fully fed the cutworms went into the soil to pupate. Such of 



