Abstract
At 25°C, the nymphal diapause of Carbula humerigera was induced in the second to fifth instars by short stationary photoperiods of 10 to 13 hr and averted by long of 14 to 16 hr. In a photoperiod of 13.5 hr, the nymphal development was transitional. At 20°C, the nymphal diapause was induced by a photoperiod of 14 hr or shorter and averted by photoperiods of 15 to 16 hr. The critical daylength lies between 14 and 15 hr. Therefore, temperature exerted a modifying effect on the critical photoperiod. The nymphal development was affected by changes in photoperiod and the adult emergence tended to be more synchronized by increasing photoperiod.
