Techniques used to determine the mating behaviour of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in relation to host plants
This paper describes techniques to determine the mating success of the cotton bollworm, Helicoverpa armigera (Hübner), and gives an example of the efficacy of the techniques in the field. Various wing-clipping methods to immobilise female moths in mating tables were compared. The removal of the right fore- and hindwing was most effective. Wing-clipped females were less likely to be mated than normal-winged females. However, enough mating occurred for the wing-clipped females to be used in field experiments. There was no consistent effect of age of females (2–5 days) or density (1, 2 or 3 per mating table) on mating success. Mating tables were used to determine the mating success of H. armigera in various crops in the Darling Downs, Queensland. A preliminary field experiment was conducted to investigate the mating success of H. armigera on cotton, non-flowering and flowering sunflower and fallow land. Laboratory-reared wing-clipped virgin females aged 2–5 days were placed singly or in groups in mating tables in the crops 1 h prior to sunset. Dissection the following morning determined whether they had been mated. Moth abundance was assessed using light and pheromone traps. The preliminary field experiment showed that host plants did not significantly influence the chance of a female moth being mated, despite substantial variation in moth abundance between the crops.