EFFECT OF HOST DEPRIVATION ON EGG QUALITY, EGG LOAD, AND OVIPOSITION IN A SOLITARY PARASITOID, CHETOGENA-EDWARDSII (DIPTERA, TACHINIDAE)

Solitary parasitoids are limited to laying one egg per host because la rvae compete within hosts. If host encounter rate is low, females shou ld not increase the number of eggs/host in response. The tachinid fly, Chetogena edwardsii, was used to evaluate the effect of host deprivat ion on egg accumulation, oviposition behavior, and egg quality in a so litary parasitoid. Females deprived of hosts for 2-7 days accumulate a bout 1 day's supply of eggs. Egg output of deprived females once hosts are restored does not differ from that of control females. Deprived f emales retain one egg in the uterus where it undergoes embryogenesis. Maggots emerging from retained eggs are more likely to survive in host s molting in 40 h or less after receipt of an egg than are maggots eme rging from eggs fertilized shortly before oviposition. Egg retention i s a consequence of host deprivation that permits females to broaden th e range of hosts they can exploit to include soon-to-molt hosts and po ssibly multiply parasitized hosts.