ABSTRACT
There are two Helicoverpa species of agricultural importance in Australia, the old world species Helicoverpa armigera (Htibner), and the endemic Helicoverpa punctigera Wallengren. Though closely related and similar in appearance, the two species differ in their distributions, seasonal abundance and feeding preferences (Zalucki et al. 1986; Fitt et al. 1989). The pest status of these two species derives from a suite of physiological, behavioural and ecological characteristics, which enable them to survive in unstable habitats and, in turn, to successfully colonize and exploit agricultural systems. The four major characteristics which contribute to Helicoverpa spp. pest status are: polyphagy, high mobility, high fecundity and a facultative diapause (Fitt 1989). Adult movement at scales ranging from a single field to geographic regions is crucial to the dynamics of Helicoverpa populations and requires that both research and management adopt effective regional approach.
