THE BERTHA ARMYWORM (MAMESTRA-CONFIGURATA) (LEPIDOPTERA, NOCTUIDAE) IN WESTERN CANADA

The bertha armyworm has been recognized as an agricultural pest in wes tern Canada for more than 85 years, during which time outbreaks have o ccurred at irregular intervals. The first major outbreak occurred in S askatchewan in 1944 on the new crop, rapeseed. The development of cano la as a major crop led to a dramatic increase in the economic damage c aused by the bertha armyworm and resulted in the widespread use of ins ecticides for control. Discovery of a species-specific pheromone and d evelopment of an adult monitoring system in the late 1970s and early 1 980s led to a method for providing producers with early warning of pot ential for crop damage. In parallel, methods for estimating larval pop ulations were developed but are in need of improvement. Refinement of these methods has the potential to provide a more accurate indication of damage risk for producers of canola. Control of bertha armyworm rel ies heavily on the use of chemical insecticides, emphasizing the need for development of integrated management strategies.