Natural enemy abundance and pest density at difference scales of crop diversification

Summary

The aim of this study was to find the appropriate scale of crop diversification with regard to pest density, natural enemy abundance and natural enemy conservation in cropping systems through field experiments in Wageningen, the Netherlands. The spatial and temporal distribution of natural enemies were determined by visual assessment, beat sampling and pitfall trap sampling at three scales of crop diversification including field, strip and plant scales. Results suggest that crop diversification is positively related to biological control potential while the difference of plant and strip scales of crop diversification need further study. It is still vital to figure out mixing crop to the appropriate scale rather than blindly pursue the more diverse the better. The biological control function of non-crop habitats was also tested by abundance and movement of natural enemies. It demonstrated that non-crop habitats like hedges can conserve natural enemies as beneficial habitats especially after crop harvest. It is recommended that those non-crop habitats are installed in cropping systems for promoting pest control potential.