Sexual behaviour of Heliothis peltigera (Lepidoptera: Noctuidae)

The sexual behaviour of Heliothis peltigera (Denis & Schiffermüller) was studied in the laboratory. Calling activity was very low during the first five hours of scotophase and then increased sharply, particularly in six-to eight-day old females. Peak activity was observed, in all ages tested, between eight and nine hours into scotophase. Calling in six-day old females was significantly higher than in two-day old females but no significant differences were detected between four-to eight-day old females. Maximal amounts of pheromone were found in the pheromone glands of five-to eight-day old females in the second half of scotophase. Male activity was monitored in a wind tunnel. There was no response to pheromone lures during the first two days, then flying activity increased sharply and maintained its high level until the eighth day. Peak activity was observed between six and eight hours into scotophase. Mating activity was very low during the first five hours of scotophase and then increased sharply, with 61.8% of the observed pairs mating between six and eight hours into scotophase. The sexual behaviour of H. peltigera was very similar to the reported behaviour of the sympatric species Helicoverpa armigera (Hübner) indicating that the reproductive separation of the two species is not affected by temporal factors, but depends mainly on the species-specific pheromone blends. © 1992, Cambridge University Press. All rights reserved.