8 MONTANA EXPERIMENT STATION BULLETIN 484 



1952 an early spring field cricket infestation occurred in a local- 

 ized area of Big Horn County involving approximately four farms. 

 The crickets were moving from stubble fields into the winter 

 wheat fields and seriously damaging the crop. A combination 

 spray of toxaphene and chlordane controlled this infestation. The 

 insecticides were used in a combination of Yi pound of chlordane 

 per acre and one pound of toxaphene per acre. 



EUROPEAN EARWIGS (Forficula auricularia) 



This unsightly insect is now common in all of Montana west 

 of the Continental Divide and in the southwestern portion of Mon- 

 tana east of the Continental Divide. Unusually severe populations 

 occurred in the late summer of 1952 in many homes and gardens 

 of northwestern Montana. Both chlorinated hydrocarbon insecti- 

 cidal sprays and baits were used to combat these infestations. 



SPITTLEBUGS (Cercopidae family) 

 In 1952 spittlebugs became quite prevalent over much of 

 Montana west of the Continental Divide. For the most part their 

 activities were confined to weeds; however, occassionally gardens 

 were invaded with some damage resulting. They were also ob- 

 served to be present in alfalfa fields. No cases of damage to field 

 crops were reported. 



WESTERN CHINCH BUGS (Blissus occiduus) 

 During the reporting period, the western chinch bug occurred 

 only in 1951 where it caused damage to crested wheat grass in 

 Teton County and to several barley fields in Fergus County. These 

 infestations were localized but the damage was severe. 



INSECTS DESTRUCTIVE OF FIELD CROPS 



SMALL GRAINS 



CRESTED WHEAT PLANT BUGS (Labops hesperus) 



In 1951 five or six spring and winter wheat fields in Choteau 

 County received severe marginal damage from crested wheat 

 plant bugs which had moved from adjacent crested wheat grass 

 fields. Similar situations were reported near Pryor, Montana, in 

 1938. Similar damage also occurred in several scattered areas 

 throughout Montana in 1952. Such infestations were, readily con- 

 trolled with a marginal spray application of two to three pounds 

 of DDT per acre. 



Extremely severe damage to crested wheat grass plantings 

 occurred in Ravalli, Missoula, and Cascade counties in 1952. In 

 some cases the damage was so severe that when accompanied by 

 grazing it resulted in crested wheat grass plantings being killed. 



