Balancing between Host- and Food-foraging by the Host-feeding Pupal Parasitoid Pimpla luctuosa Smith (Hymenoptera : Ichneumonidae)

Laboratory experiments were conducted on the host:feedin gparasitoi dPimpla luctuosa to determine how needs for hosts and non-host food influence the foraging decision of whether to forage for hosts or for food. Females provided with both hosts and water lived longer than females provided with only water but sherter than female sprovide dwith honey-water and hosts, indicating that host hemolymph and carbohydrate are both needed to maximize longevit yI.n the wind tunneL females and males that had fed on honey responded to honey odor while those fed on sucrose water or only water did not respond to honey odor, suggesting the effect of leaming. Wheri given a choice between vanilla odor associated with host sand honey odor, most of starved female sthat had experienced these two odors preferre dhoney over vanilla, but many of honey-fed females preferred yanMa. The Tesponse by female sgive nonly hosts and water for 2 days was intermediate between starved and well-fed females. When give nonly host sand water for 4 days ,many female sdid not exhibit fligh tresponse to odors. These results suggest that R luetuosa females make choices between host-foraging and food-foraging based on their continuously shifting needs for hosts and for fbod.