MONTANA INSECT PESTS, 1951-1952 11 



Broadwater County during June 1952. The infestations were large- 

 ly on winter wheat and in all cases the wheat was far enough ad- 

 vanced so that the leaf feeding damage inflicted by the sawfly 

 was not of economic importance. This was the only known oc- 

 currence of this insect during the biennium. 



CORN 



EUROPEAN CORN BORER (Pyrausta nubilalis) 



The first known occurrence of European corn borer in Mon- 

 tana was discovered October 20, 1951, in a corn house near Savage. 

 Corn borer larvae were found to be tunneling the cobs of this seed 

 corn. 



A survey in 1952 revealed very light infestations of European 

 corn borers in irrigated corn in Prairie, Dawson, and Richland 

 counties. No borer infestations were found in dryland corn. To 

 date the borer has not been found in alarming numbers. An ex- 

 tension program is being organized to advise farmers what to look 

 for in determining the presence of corn borers and to acquaint 

 farmers with methods of handling corn fields and products from 

 those fields in such a manner as to prevent the borers from over- 

 wintering successfully. 



CORN EARWORM (Heliothis armigera) 

 The corn earworm was not prevalent during the first year of 

 the biennium. In late July of 1952 numerous moderate to severe 

 infestations were found on irrigated field and garden corn in the 

 southeastern, southcentral, and western parts of the state. 



BUMBLE FLOWER BEETLE (Euphoria inda) 

 A single infestation of bumble flower beetles occurred on 

 corn in Cascade County during the late summer of 1951. Consider- 

 able damage to the corn ears was experienced. This was the only 

 infestation observed or reported during the biennium. 



ALFALFA AND CLOVER 



ALFALFA SEED CHALCID (Bruchophagus gibbus) 



Very light and widely scattered infestations of alfalfa seed 

 chalcid occurred over most of the alfalfa seed producing areas in 

 the state during the biennium. No inquiries were received re- 

 garding this insect, and no extremely severe infestations are 

 known to have occurred. 



ALFALFA WEEVIL (Hyper a postica) 



All, or parts of, Madison, Park, Sweetgrass, Stillwater, Car- 

 bon, Golden Valley, Fergus, Phillips, Petroleum, Garfield, Mus- 



