Induction of adult diapause and of low and high reproductive states in a parasitoid wasp, Ooencyrtus nezarae, by photoperiod and temperature

Abstract

AbstractOoencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) was reared on eggs of Riptortus clavatus (Thunberg) (Heteroptera: Alydidae) at various temperatures under long‐day (L16:D8) or short‐day (L10:D14) conditions. There was no diapause during egg, larval or pupal stages under any set of conditions examined. However, at 15 °C under short‐day conditions, vitellogenesis was arrested in all adult females and they entered diapause. At 15 °C under long‐day conditions, or at 20 °C under short‐day conditions, some adult females entered diapause. Under the latter set of conditions, the adult females laid eggs but they laid fewer eggs than under long‐day conditions. Even at 25 °C, under short‐day conditions, adult females laid fewer eggs than under long‐day conditions, and this low rate of oviposition was attributed to the retarded development of ovaries. Diapause adults reared at 15 °C were more resistant to low temperature than nondiapause adults reared at 25 °C.