Modeling the effects of trap crop attraction strength, patch dispersion, and biological control on pest suppression.

Trap cropping has long been an important component of integrated pest management schemes in agricultural ecosystems. Spatial dispersion and the strength of attraction of trap crops relative to principal crops, along with insect movement behavior, may all moderate the efficacy of trap cropping in controlling pests. Here we employ a simple differential-equation patch model to explore the interplay of trap cropping and biological control. In particular, we vary attraction strength to trap crops along with predator foraging behavior (mobility and directedness) to determine the relative influences of these factors on herbivore suppression. Our results highlight the fact pest suppression is mediated by the relative palatability of trap crops to both pests and predators, and somewhat mediated by the spatial dispersion of trap crops. We discuss the potential for using trap crops in combination with natural enemies to boost pest suppression in annual cropping systems.