Differences in foraging behaviour between virgin and mated aphid parasitoids (Hymenoptera: Aphidiidae)

Abstract

The influence of mating status on foraging behaviour was examined in the parasitoid wasps Aphidius smithi Sharma &Subba Rao, Ephedrus californicus Baker, Monoctonus paulensis (Ashmead), Praon pequodorum Viereck, and Lysiphlebus testaceipes Cresson (Hymenoptera: Aphidiidae). Virgin females of A. smithi, M. paulensis, and P. pequodorum abandoned bean shoots infested with pea aphid, Acyrthosiphum pisum (Harris), earlier than did their mated counterparts. Virgin females of all species except L. testaceipes (host Aphis fabae Scop.) attacked fewer aphids within a patch than did mated females, and parasitized fewer hosts in a 2-h period. Females therefore tend to produce a smaller brood within a patch when unable to fertilize their eggs and produce daughters. Mated females of A. smithi and M. paulensis superparasitized more aphids than did unmated females of these species. Females of all species mated successfully and produced daughters after ovipositing as virgins. The possible fitness consequences of distinct virgin oviposition tactics are discussed.