ABSTRACT
A model has been developed which simulates the temporal and spatial dynamics of greenhouse whitefly and the parasitoid Encarsia formosa in a tomato crop. The pest-parasitoid interaction is based on the local searching and parasitization behaviour of individual parasitoids in the whitefly-infested crop. The model comprises several submodels for (a) the parasitoid’s foraging behaviour, (b) the whitefly and parasitoid population development, (c) the spatial distribution of whitefly and parasitoid in the crop, and for (d) leaf production, The model will allow us (1) to explain why the parasitoid can control whiteflies on some crops and not on others in large commercial greenhouses, (2) to improve introduction schemes of parasitoids for crops where previous control was ineffective, (3) to predict effects of changes in cropping practices (e.g. greenhouse climate, choice of cultivars) on the reliability of biological control, and finally (4) to develop criteria for the selection of natural enemies.
