Parasitoid searching efficiency links behaviour to population processes

Parasitoid searching efficiency is central to parasitoid-host population dy namics, to the evolution of parasitoid and host behaviour, and to the appli cation of parasitoids as natural enemies of insect pests in biological cont rol. Students of parasitoid behaviour attempt to explain variability in par asitoid searching behaviour, while population dynamicists are more concerne d with variation in the outcome of parasitism and how this affects the spat ial distribution of host mortality and population stability. Unfortunately the links between behaviour and population processes have been rarely expli citly made. Parasitoid searching efficiency potentially links behaviour to population processes since it affects the temporal and spatial heterogeneit y of host attacks. But which behaviours determine searching efficiency? In the present paper I attempt to identify some of these key behaviours. They involve responses to cues that help parasitoids to assess important charact eristics of the spatial distribution of their hosts such as which food plan ts hosts are feeding on, the host distribution pattern on food plants and t he host density and patch quality. Plant information plays an essential rol e in many of these processes. In the present paper I will discuss both the behavioural mechanisms involved and the potential effect for population pro cesses.