Abnormal Photoperiodic and Phototactic Reactions of the Beetle, Epilachna vigintioctopunctata, Reared on Sliced Potatoes

Epilachna uigintioctopunctata could be reared on sliced potatoes for two generations, but adults obtained were smaller than the normal adults fed on thehost foliage, and laid less number of eggs. These adults showed abnormal phototatic response, and some of them continued to oviposit when they were transfered into short-day photoperiod. Adults reared on sliced potatoes only after the adult emergence could respond to short-day photoperiods to stop their ovarain development, but they did not enter diapause. The inhibition of diapause incidence seemed to be due to the incompleteness of fat body development by the nutritional deficiency in potato tubers.