Published online by Cambridge University Press: 31 May 2012
The bertha armyworm, Mamestra configurata Walker, is a major pest of canola in western Canada. In 1994, 1995, and 1996 more than 670 000, 650 000, and 250 000 ha of canola were sprayed for bertha armyworm, respectively (Anonymous 1994, 1995, 1996). Despite the current trend towards increased acreage of canola production in western Canada, canola acreages declined markedly in 1996 from that planted in 1995 (Saskatchewan Agriculture and Food Statistical Facts 1996) in part because of the perception by farmers of the impact of bertha armyworm outbreaks in 1994 and 1995. Much research has been carried out in western Canada on the bertha armyworm with the aim of developing an integrated pest management program which includes the understanding of its biological control agents. Turnock (1984) reported that the native parasitoid complex of larval M. configurata consists of five species of Hymenoptera and 10 species of Diptera. Only two of these, namely Banchus flavescens Cresson (Hymenoptera: Ichneumonidae) and Athrycia cinerea (Coquillett) (Diptera: Tachinidae), have large negative impacts on its populations (Wylie and Bucher 1977).