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 (T-o) (12.65 degrees C). When immatures were stored at 14.8 degrees C, they had emergence rates comparable to the control after 8 weeks, which indicated high survival rates at that temperature. Storage at 10.1 degrees C was deleterious to parasitoid survival (17-100% mortality), especially when individuals were stored without preconditioning. Preconditioning by exposing the individuals to 14.8 degrees C for 1 week before storage at 10.1 degrees C improved parasitoid survival and fecundity compared to those without preconditioning. Effects were severe when A. ananatis individuals were stored at 10.1 degrees C while in the prepupal stage because most failed to develop further. Individuals that were preconditioned at 14.8 degrees C before being held at 10.1 degrees C experienced no mortality in the prepupal stage. The I week of storage at 14.8 degrees C allowed all prepupae to develop into the pupal stage before they were transferred to 10.1 degrees C. Prepupal to early pupal stages can only be stored for brief periods (< 2 weeks) at 10.1 degrees C because prolonged exposure is lethal. (c) 2005 Elsevier Inc. All rights reserved.