Environmental Influences on the Flight and Migratory Potential of 'Helicoverpa Punctigera' and 'H. Armigera' (Lepidoptera: Noctuidae)

Abstract

This study examined the role of environmental factors in influencing the flight capacity of 'Helicoverpa punctigera' (Wallengren) and 'H. armigera' (Hiibner) moths (Lepidoptera: N octuidae ). Flight capacity of female and male moths were measured by means of a tethered flight technique. Flight capacity was found to be age dependent in both species. In 'H. punctigera', flight ability increased from the first night following emergence up to night 4, and was maintained at least until night 10. In 'H. armigera', a peak in flight capacity occurred on night 4, followed by a decline with increasing age. Long flying(>5 hr duration) moths were evident in both species from the night following emergence. Attainment of reproductive maturity was rapid in both species, with 91% of 'H. punctigera' and 77% of 'H. armigera' ovipositing by night 3. Hence, the increase in flight capacity recorded for both species during early adult life is coincident with the onset of reproductive activity. Both species retain the capacity for extensive inter-crop and inter-regional movement throughout most of the reproductive phase of their adult lives. Neither successful mating or the absence of adult food sources influenced flight capacity during early adult life.