MONTANA INSECT PESTS, 1955-1956 13 



FLEA BEETLE LARVAE (Coleoptera: Chrysomelidae) 



In Yellowstone County in 1955 bean fields showed damage re- 

 sembling that of the seed corn maggot. However, examination showed 

 that flea beetle larvae were feeding on the sprouted seeds. 



INSECTS DESTRUCTIVE TO GARDEN AND TRUCK CROPS 



In general, insects which feed on these plants were comparatively 

 scarce during the biennium. Leaf hoppers are almost always a prob- 

 lem on truck crops in irrigated valleys since they move into the areas 

 from the surrounding drying range during the summer. 



CABBAGE ROOT MAGGOT (Hylemya brassicae) 



This pest continues to be a problem but not an important one where 

 insecticidal recommendations are followed. 



INSECTS DESTRUCTIVE TO FRUIT CROPS 



BLACK CHERRY FRUIT FLY (Rhagoletis fausta) 



This insect continues to be the number one problem of com- 

 mercial cherry producers in the western part of the state. Although 

 most orchard operators follow approved programs of control, there 

 are still enough unattended and backyard trees to provide continuous 

 reinfestation. It should be stated, however, that much progress has 

 been made in eliminating abandoned trees and other sources of in- 

 festation. The cherry fruit fly is known to occur in Ravalli, Missoula, 

 Lake, and Flathead counties. 



PLUM NURSERY MITE (Vasates fockeui) 



This mite, first reported as a serious pest of cherries in 1954, 

 was seldom seen during the 1955 growing season. A serious local 

 infestation occurred during 1956 on the east shore of Flathead Lake. 



FOREST TENT CATERPILLAR (Malacosoma disstria) 



During 1955 this pest was present in Toole County. It was 

 present on apple trees in Broadwater and Hill counties in 1956. 



CODLING MOTH (Carpocapsa pomonella) 



This pest needs control annually throughout the apple-raising 

 counties west of the divide. In addition it does damage in manv 

 counties east of the divide. 



