Abstract
Diapause in Hippodamia tredecimpunctata (Linnaeus) can be inhibited by exposing adult females to photoperiod regimens of LD 16:8 or 14:10 hours. Exposing adult females to a photoperiod of LD 12:12 hours initiates diapause. The photoperiod to which the egg, larval, and pupal stages are exposed has no effect on the developmental rate and has little effect on adult diapause status.