Diapause in a New Zealand strain of codling moth (Cydia pomonella Linnaeus [Lepidoptera: Olethreutidae]) was induced in larvae by photoperiods of 15 h or less. Once diapause had been initiated, it could not be terminated by any combination of conditions tested for at least 20 days after cocooning. In diapausing larvae a low rate of pupation occurred at 25 ~ under a long day (18 h) photoperiod. A high rate of pupation was achieved under a long day regime when larvae were decocooned, and provided with apple as nourishment. Diapause could be terminated predictably in 94-100~o of larvae by 1) conditioning at 15 ~ and constant darkness for periods of 40-100 days, then 2) chilling at 2 + 2 ~ and constant darkness for 20-50 days followed by 3)any post-chill condition periods at 25 ~ 18 h photoperiod. Complete diapause termination was achieved when 100 days conditioning was followed by 30 days or 50 days post-chill period. Under these conditions, 76~ termination occurred in the post-chill period after 10 days, and 93~o after 25 days.To terminate diapause in codling moth larvae, we recommend that a 100 days conditioning followed by 30 days chilling and 50 days post chilling periods be used.