MONTANA INSECT PESTS, 1951-1952 15 



bage maggot during the biennium was neither more nor less se- 

 vere than in previous years. This garden pest appears to be com- 

 mon throughout the entire state and is readily controlled with a 

 chlordane treatment at the time of planting. 



IMPORTED CABBAGEWORM (Pieris rapae) 

 No severe outbreaks of this pest of cruciferae were reported 

 or observed during 1951. This insect did occur over most of the 

 state causing considerable damage, particularly in many western 

 Montana gardens, in 1952. 



ROOT CROPS 



ONION MAGGOT (Hylemya antiqua) 



Reports and inquiries indicate that onion maggot infestations 

 in gardens were normal during the biennium. Chlordane treat- 

 ment at the time of planting appears to be successful in prevent- 

 ing onion maggot damage. 



ONION THRIP (Thrips taboci) 

 Onion thrips were present in Ravalli County during the sum- 

 mer of 1952. They were not found to be causing economic damage. 



ASPARAGUS 



ASPARAGUS BEETLE (Criocerus asparagi) 

 During 1952 asparagus beetles were found and reported to 

 be causing economic damage to asparagus plantings in western 

 Montana, particularly in Ravalli and Lake counties. No reports 

 were received during 1951. 



INSECTS DESTRUCTIVE OF FRUIT CROPS 

 ORCHARDS 



BLACK CHERRY FRUIT FLY (Rhagoletis fausta) 

 1951 



In 1951 there was a limited sweet cherry crop. Therefore, no 

 extensive control or trapping program was conducted by the 

 growers. Experimentation comparing the efficiency of trap board 

 and attractant type traps as well as various cherry fruit fly con- 

 trols was conducted. 



1952 



In 1952 the sweet cherry crop was above average. An in- 

 tensive trapping program was conducted to determine emergence 

 dates and adult populations. In addition, two types of insecticidal 

 controls were compared. For these purposes two orchards with 

 histories of fruit fly infestations were selected. One of the orchards 



