Abstract
The evaluation of Eurithia consobrina (Meigen) as a candidate for introduction against bertha armyworm, Mamestra configurata (Walker) (Lepidoptera: Noctuidae), in western Canada included studies of its host range, distribution, synchronization with host, constancy, abundance and life history in Europe. In addition, its diapause induction and its coldhardiness were compared with those of the target host M. configurata and its native tachinid parasitoid, Athrycia cinerea (Coq.). E. consobrina was found to fit criteria for a successful biocontrol agent reasonably well. It also had the potential to fill a largely unoccupied niche in the parasitoid complex of M. configurata. E. consobrina has a facultative diapause of the long-day type, similar to A. cinerea, but is less sensitive to diapause-inducing conditions. E. consobrina is at least as coldhardy as A. cinerea and more coldhardy than M. configurata. Laboratory exposures to temperatures of 0 C for 140 days apparently selected for greater coldhardiness, and later generations survived exposures of 140 days at -15 C without significant mortality. Adult E. consobrina were released at three locations in Manitoba in 1986 and 1987, but establishment has not been confirmed.