ABNORMAL PHOTOPERIODIC AND PHOTOTACTIC REACTIONS OF THE BEETLE, EPILACHNA-VIGINTIOCTOPUNCTATA, REARED ON SLICED POTATOES

Epilachna vigintioctopunctata could be reared on sliced potatoes for two generations, but adults obtained were smaller than the normal adults fed on the host foliage, and laid less number of eggs. These adults showed abnormal phototactic 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 photoperiod to stop their ovarian 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. © 1979, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.