Cascade effects of crop species richness on the diversity of pest insects and their natural enemies

Abstract
Understanding how plant species richness influences the diversity of herbivorous and predatory/parasitic arthropods is central to community ecology. We explore the effects of crop species richness on the diversity of pest insects and their natural enemies. Using data from a four-year experiment with five levels of crop species richness, we found that crop species richness significantly affected the pest species richness, but there were no significant effects on richness of the pests’ natural enemies. In contrast, the species richness of pest insects significantly affected their natural enemies. These findings suggest a cascade effect where trophic interactions are strong between adjacent trophic levels, while the interactions between connected but nonadjacent trophic levels are weakened by the intermediate trophic level. High crop species richness resulted in a more stable arthropod community compared with communities in monoculture crops. Our results highlight the complicated cross-trophic interactions and the crucial role of crop diversity in the food webs of agro-ecosystems
Description
CITATION: Shi, P. et al. 2014. Cascade effects of crop species richness on the diversity of pest insects and their natural enemies. Science China Life Sciences, 57(7): 718-725, doi:10.1007/s11427-014-4681-7.
The original publication is available at http://link.springer.com/journal/11427
Keywords
Crop species richness -- Cascade effects, Species richness of pest insects, Natural enemies of pests insects, Pest insects -- Diversity
Citation
Shi, P. et al. 2014. Cascade effects of crop species richness on the diversity of pest insects and their natural enemies. Science China Life Sciences, 57(7): 718-725, doi:10.1007/s11427-014-4681-7.