12 MONTAxN'A EXPERIMENT STATION BULLETIN 526 



POTATO PSYLLID (Paratrioza cockerelli) 



Indications that this pest may be building up in the state were 

 shown by damage to fields in Broadwater and Yellowstone counties. 

 No economic infestations have been reported, but indications of psyllid 

 activity were quite common in 1955. Less activity was noticed in 1956. 



WIRE WORMS (Coleoptera: Elateridae) 



Wireworms are a problem on potatoes mainly in the western 

 part of the state. Flathead, Lake, Missoula, and Powell counties 

 have had economic infestations during the biennium. 



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Sugar Beet Insects 



WEB WORM (Loxostege sticticalis) 



Webworms were present in the Milk River Valley in mild to 

 moderate infestations in 1955. In 1956 they were important locally 

 in Yellowstone and Carbon counties. Noninjurious second generation 

 worms were received by this office from many scattered points east 

 of the mountains. They were feeding mostly on Russian thistle and 

 other unimportant weeds. 



FLEA BEETLES (Epitrix sp.) 



Early in the growing season of 1955 one of the most severe in- 

 festations on record occurred on sugar beets in Richland Count}'. 

 Prompt application of DDT dust over a large area alleviated the 

 situation. 



Insect Pests of Peas and Beans 



SEED CORN" MAGGOT (Htjlemya cilicrura) 



At least two infestations of this pest occurred in Yellowstone and 

 Carbon counties in 1955. Replanting later in the season after the 

 soil had partially dried produced a crop on the previously infested 

 fields. No infestations were reported during 1956. 



BE AX WEEVIL (Acanthoscelides obtectus) 



One infestation in stored beans in Big Timber was reported in 

 1955. Either heat treatment or fumigation will control this insect 

 in stored beans. 



