14 MONTANA EXPERIMENT STATION BULLETIN 484 



County in 1951. This is the only infestation observed or reported 

 during the biennium. 



SUGAR BEETS 



SUGAR BEET ROOT MAGGOT (Tetanops aldrichi) 



Several infestations of sugar beet root maggots were reported 

 in Richland County and in western Montana in 1952. This is the 

 only occurrence reported or observed during the biennium. Seed 

 treatment with aldrin appears to control this pest. 



SUGAR BEET ROOT APHID (Pemphigus betae) 



No economic infestations of sugar beet root aphids were re- 

 ported or observed during the biennium. 



BEET WEB WORM (Loxostege sticticalis) 

 Only one infestation of beet webworm was reported or ob- 

 served during the biennium. This single occurrence was a moder- 

 ate infestation found on sugar beets in Prairie County in late 

 August 1952. In this particular case the beets were far enough ad- 

 vanced so that control measures were not advisable. 



SPINACH CARRION BEETLE (Silpha bituberosa) 

 No economic infestations of spinach carrion beetles were re- 

 ported or observed during the biennium. 



SPINACH LEAF MINER (Pegomya hyoscyami) 

 Light to moderate infestations of spinach leaf miners occur- 

 red on sugar beets in Yellowstone County during June of 1952. 

 Control measures were not attempted, and this is the only known 

 occurrence of this insect during the biennium. 



PEAS AND BEANS 



PEA APHID (Macrosiphum pisi) 

 Several fields of canning peas in Carbon County were mod- 

 erately to heavily infested with this sucking insect in 1951. Con- 

 trol measures with tetraethyl pyrophosphate were instigated. 

 Other than normal populations in alfalfa fields, no further infes- 

 tations were reported or observed during the biennium. 



PEA WEEVIL (Bruchus pisorum) 

 No economic infestations of pea weevils were observed or re- 

 ported during the biennium. 



INSECTS DESTRUCTIVE OF GARDEN AND TRUCK CROPS 



CRUCIFERAE 



CABBAGE MAGGOT (Hylemya brassicae) 

 Reports and observations indicate that the occurrence of cab- 



