Blumberg, D., Division of Entomology, The Volcani Center, A.R.O., Bet Dagan, Israel

During autumn and winter (October-February)Cybocephalus nigriceps nigriceps (J. Sahlberg) adults undergo a facultative diapause. The diapausing adults agregate in hiding places, development of the ovaries is arrested, and prey consumption is lowered. Diapause can be prevented by exposure to a long-day photoperiod (16 hr light) at high temperatures (29° and 32°C). Diapause is induced mainly by short-day conditions, but the termination of diapause is affected by both photoperiod (long-day conditions) and temperature (29°, 32° and 34°C). In mature females, diapause induction causes ovarian degeneration. The induction or inhibition of adult diapause is affected by photoperiods occurring during larval development as well as during adult life. © 1976 Le François.