Using Novel Host–Parasitoid Associations for Biological Control of Native Pests

Abstract

<i>Importation biological control of exotic insect pests traditionally uses a method of reuniting pests with their long-associated natural enemies from the aboriginal home of the pest. In the case of native pests, however, long-associated natural enemies are already present but fail to exert economic control of the pest. In this situation, an alternative importation approach is to create novel pest–natural enemy associations where the natural enemy and target pest have no historical association. Novel pest–natural enemy associations have been used effectively in a number of instances for biological control of native pests. Novel associations can be effective but, as in all instances where exotic organisms are purposefully introduced, care must be exercised to avoid introducing novel natural enemies that may attack nontarget hosts. We believe that novel pest–natural enemy associations can be used safely and effectively, by either analyzing how the natural enemies select appropriate habitats and hosts, and using this host–habitat selection strategy to predict the potential host range of the introduced natural enemy, or by avoiding natural enemies with a known broad host range.</i>