MATING-BEHAVIOR OF THE RICE STEM BORER MOTH, CHILO-SUPPRESSALIS WALKER (LEPIDOPTERA, PYRALIDAE) .2. EFFECTS OF TEMPERATURE AND RELATIVE HUMIDITY ON MATING ACTIVITY

The effects of temperature and relative humidity on mating behaviour of the rice stem borer moth, Chilo suppressalis WALKER, were investigated. Mating occurred in a wide temperature range from 8°C to 37°C, and the optimum temperatures appeared to be in the range of 15°-25°C. The high and low threshold-temperatures, 37°C and 8°C, for mating were similar to the threshold-temperatures for male response to the female sex pheromone extracts. It seems that the threshold-temperatures for mating are determined by male response. The times of mating shifted earlier with decreasing temperature. The highest incidence of female calling occurred at temperatures near 20°C. The male response was sensitive in the temperature range of 15°-25°C. The times of female calling and male response to the female sex pheromone extracts were also advanced at cool temperatures compared with warm ones. The duration of mating became shorter with increasing temperature. The relative humidity had little effect on mating percentage at 20°C and 25°C. © 1979, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.