Diapause termination in the spotted stem borer, Chilo partellus (Lepidoptera: Pyralidae) in the laboratory

The effect of temperature, photoperiod, artificial diet and water on the termination of diapause by larvae of the stem borer, Chilo partellus (Lepidoptera: Pyralidae), was studied in the laboratory. Termination of diapause as indicated by pupation was affected mainly by a combination of high temperature and a long day photoperiod. Total darkness did not prevent termination of diapause and pupation occurred also in larvae which were never exposed to water. Long days accelerated pupation, but, under 16 h daylength, termination of diapause was faster than under constant illumination. Provision of artificial diet had no effect or slowed down pupation but water decreased the time to pupation. Under 28°C, 16 h daylength and availability of water, C. partellus diapausing larvae terminated diapause and pupated in about 9 days.