Diapause Termination in Busseola fusca (Lepidoptera: Noctuidae) in the Laboratory

The effect of temperature, photoperiod, artificial diet, and water on the termination of diapause by larvae of the African maize stem borer, Busseola fusca (Fuller), was studied in the laboratory. Diapause termination as indicated by pupation was accelerated at 26°C and was slower at 23 and 28°C. Complete darkness did not prevent diapausing larvae from pupating, and long days accelerated pupation. Lack of food or water did not prevent pupation, but the survival rate of the diapausing larvae was low. The provision of artificial diet or water accelerated the emergence from diapause. At 26°C, a photoperiod regime of 16:8 (L:D) h, and adequate water, B. fusca larvae terminated diapause after 34 d. It was concluded that a combination of temperature and photoperiod played an important role in completion of diapause development in B. fusca , and water was important only as a stimulus for morphogenesis following diapause.