From behavioural studies to field application: Improving biological control strategies by integrating laboratory results into field experiments

Abstract

Biological control and integrated pest management (IPM) of tephritid fruit flies has repeatedly made use of parasitoids as natural enemies to suppress fly populations. Parasitoids, however, are selected to maximize their individual reproductive success, and thus do not necessarily maximize pest suppression at the population level. Furthermore, more than one parasitoid species within a pest-natural enemy assemblage might be available as a potential control agent. This calls for a thorough understanding of behavioural processes in pest-natural enemy interactions to select the best single species, or multiple species, to achieve pest suppression at the population level. We make a case for the importance of laboratory studies in informing field application, while acknowledging that they cannot replicate all the complexity present within an ecological community. Thus, there is still the need for integrating laboratory-based research with field application. Therefore, manipulative field studies are needed to determine whether the insights from laboratory results hold true in a more complex system. We describe how laboratory results can be used to inform field studies and predict the likelihood of success of natural enemy releases. We use the example of the natural enemy- Bactrocera dorsalis system in Africa. We show that behavioural ecology offers a powerful tool to understand species interactions on the basis of individual decisions. We further discuss how these findings can be exploited in an agricultural context to improve the control effort. Finally, we describe the need for comprehensive field studies based on the behavioural observations made in the laboratory.