The effects of photoperiod and temperature on calling behaviour and egg development of the bertha armyworm,Mamestra configurata (Lepidoptera: Noctuidae)

The effects of photoperiod and temperature on calling behaviour and the effects of temperature on the relationship between egg development and calling of virgin females of Mamestra configurata Walker were examined at 3 photoperiodic regimes and seven constant temperatures. Photoperiod affected the diel periodicity of calling and length of the daily calling period. The mean onset calling times were similar if the preceding scotophase(s) was 6–10 h long, but the onset of calling was delayed by 1–5 h if the preceding scotophase(s) was 12–18 h long. Long-term, constant temperature (from emergence until death) affected 4 aspects of calling: age at first calling, diel periodicity, length of the daily calling period, and percentage of females calling. Short-term temperature changes (during a single scotophase) affected calling in 3 ways: diel periodicity, length of the daily calling period, and percentage of females calling. The optimal temperature range for calling was, at least, 10–25°C; the upper limit and threshold were near 35 and < 5°C. The time of first calling was synchronized closely with the appearance of the first chorionated eggs in the ovaries at 10–35°C. Egg development and calling were adversely affected at 30 and 35°C. The physiological and ecological significance of the data are discussed.