Responsiveness ofPseudaletia unipuncta (Lepidoptera: Noctuidae) males, maintained as adults under different temperature and photoperiodic conditions, to female sex pheromone.

Different-agedPseudaletia unipuncta (Haworth) males, maintained as adults at 10 and 25°C under 16∶8 and 12∶12 light-dark photoperiodic regimes, were flown to a 30-μg pheromone source in a wind tunnel at 20°C. While the responsiveness of individuals reared under both photoperiodic conditions at 25 °C was similar by day 5 (65-75%), response levels of younger males showed that those reared at 16∶8 light-dark matured more rapidly than those under 12∶12 light-dark. A significant delay in the onset of responsiveness was observed for males reared under 10°C with less than 25% of individuals responding to the pheromone, even at 25 days old. At this temperature, photoperiodic conditions had no significant effect on male receptivity. When males are transferred from 10°C to 25°C 16∶ 8 light-dark, their level of responsiveness after five days was similar to control 5-day-old males reared at 25°C, 16∶8 light-dark. These results are discussed relative to the hypothesis that this species migrates in response to seasonal cues that indicate a predictable habitat deterioration.