Abstract
Female adults of Riptortus clavatus THUNBERG grown under a long-day photoperiod (16L8D, 25°C) showed prompt ovarian development and laid eggs. Under a short-day photoperiod (10L14D, 25°C), however, the ovarian development stopped, an adult diapause being induced. The diapause could be terminated for most individuals by a long-day photoperiod when there was no exposure to low temperatures. Photoperiodic sensitivity persisted throughout the adult life and diapause could be reinduced by a short-day photoperiod and reterminated by a long-day photoperiod. The critical daylengths for the termination and for the induction of diapause were between 13 hr and 14 hr at 25°C, although they differed somewhat.
