Juvenile hormone in larval diapause of the codling moth,Laspeyresia pomonella L. (Lepidopterae,Tortricidae)

Summary Whereas in last instar larvae ofL. pomonella kept under long-day-conditions (LD), the JH-titer is temporarily reduced to zero, it stays relatively high in short-day-conditioned (SD) larvae which enter diapause. Application of JH or a juvenoid to LD-larvae results in diapause, if the treated insects are kept under SD-conditions. From these results it is concluded that inL. pomonella diapause is initiated by a relatively high titer of JH during the last larval instar.