The reproductive maturity and mating status of <i>Helicoverpa armigera</i>, <i>H. punctigera</i> and <i>Mythimna convecta</i> (Lepidoptera: Noctuidae) collected in tower-mounted light traps in northern New South Wales, Australia

Abstract

Abstract The reproductive condition and mating status of female Helicoverpa armigera (Hübner), H. punctigera (Wallengren) and the mating status of the armyworm Mythimna convecta (Walker), trapped in tower-mounted light traps were studied over a four and a half year period, from November 1985 to December 1989. The traps were mounted on towers (40 and 50 m high) in two geographically distinct sites, one located at Point Lookout and the other at Mt Dowe both in north-eastern New South Wales, Australia. At the Point Lookout site, 132 females of H. armigera and 366 of H. punctigera were examined and of those, 88.7% and 89.9% were unmated and immature, respectively. Most of the remaining females of both species were mature and mated. Of the mated H. armigera females, 78.6% carried only a single spermatophore, the remainder having either two or three spermatophores. Most of the mated H. punctigera females (97.1%) carried only a single spermatophore and the remainder had no more than two. Females of M. convecta were predominantly (97.1%) unmated. At the Mt Dowe site H. punctigera adults were predominant and all 44 females of this species examined were unmated and non-gravid. Pre-reproductive flight by Helicoverpa spp. and M. convecta is considered as an important component of the life-history strategies of these insects. Flexibility in the timing and spacing of reproductive effort is seen as enabling colonization of heterogeneous environments.