Effects of cool storage on Anagyrus ananatis Gahan (Hymenoptera: Encyrtidae)

Studies were conducted to determine the survival and reproduction of Anagyrus ananatis Gahan (Hymenoptera: Encyrtidae) individuals following cool storage above and below its developmental threshold (To) (12.65 °C). When immatures were stored at 14.8 °C, they had emergence rates comparable to the control after 8 weeks, which indicated high survival rates at that temperature. Storage at 10.1 °C was deleterious to parasitoid survival (17-100% mortality), especially when individuals were stored without preconditioning. Preconditioning by exposing the individuals to 14.8 °C for 1 week before storage at 10.1 °C improved parasitoid survival and fecundity compared to those without preconditioning. Effects were severe when A. ananatis individuals were stored at 10.1 °C while in the prepupal stage because most failed to develop further. Individuals that were preconditioned at 14.8 °C before being held at 10.1 °C experienced no mortality in the prepupal stage. The 1 week of storage at 14.8 °C allowed all prepupae to develop into the pupal stage before they were transferred to 10.1 °C. Prepupal to early pupal stages can only be stored for brief periods (<2 weeks) at 10.1 °C because prolonged exposure is lethal.