Effects of Intraspecific Competition and Host-Parasitoid Developmental Timing on Foraging Behaviour of a Parasitoid Wasp

Abstract

In a context where hosts are distributed in patches and susceptible to parasitism for a limited time, female parasitoids foraging for hosts might experience intraspecific competition. We investigated the effects of host and parasitoid developmental stage and intraspecific competition among foraging females on host-searching behaviour in the parasitoid wasp Hyposoter horticola. We found that H. horticola females have a pre-reproductive adult stage during which their eggs are not mature yet and they forage very little for hosts. The wasps foraged for hosts more once they were mature. Behavioural experiments showed that wasps’ foraging activity also increased as host eggs aged and became susceptible to parasitism, and as competition among foraging wasps increased.