Reproductive-Behavior and Pheromone Trapping of The Common Armyworm, Mythimna-Convecta

The common armyworm, Mytbimna convecta (Walker) (Lepidoptera : Noctuidae) is an important pest of cereals, pastures and forage crops throughout Australia (Smith & McDonald, 1986). Outbreaks are sporadic and largely unpredictable. Pheromone traps might be useful tools for providing an early warning of incidence, and hence better prediction of outbreaks. Little is known of the reproductive biology of M. convecta. The components of the female sex pheromone have been identified (C. Whittle & T. Bellas, pers. conim.). Initial field tests showed that very few males were caught in traps baited with either the synthetic pheromone or live females (G. McDonald, pers. comm.). In this paper, we report observations on the calling behaviour of virgin M. convecta females in the laboratory as related to age, time of the scotophase, and environmental factors, particularly temperature and photoperiod. Results from field trials using the synthetic sex pheromone and live females in traps are also presented.