Abstract
Nymphs of Carbula humerigera collected in the field at Hirosaki matured synchronously as adults from late June to early July. Females did not lay eggs before the summer solstice. Rearing under natural daylengths at 25°C indicated that increasing daylengths suppressed oviposition and decreasing ones promoted it. Nymphal diapause was induced in the third to fifth instars by short photoperod, apparently maintained by decreasing photoperiod, and terminated near the time of the winter solstice.
