Analysis of landscape-scale insect pest dynamics and pesticide use: an empirical and modeling study

作者：O'Rourke Megan E; Jones Laura E^*

来源：Ecological Applications, 2011, 21(8): 3199-3210.

• Bacillus thuringensis
• Diabrotica virgifera
• integrated pest management
• landscape ecology
• life history
• Ostrinia nubilalis
• source-sink dynamics
• spatially explicit modeling
• Zea mays

Diverse agricultural landscapes help support many ecosystem services, including insect pest suppression. Yet questions remain about how landscape diversification affects insects with differing life histories, and how interactions between pest management and land use alter insect population dynamics. Here we introduce empirical data illustrating how population dynamics and pest management of two economically important insect pests in maize (Zea mays), the European corn borer (ECB; Ostrinia nubilalis) and the western corn rootworm (WCR; Diabrotica virgifera), may vary with land use. We then explore the role of landscape in agricultural pest suppression with a spatially explicit computational model of herbivore population dynamics that includes pest management measures and insect life-history parameters (diet breadth, dispersal distance, and reproductive rate). While field results showed that WCR densities were lower in diverse than in simple agricultural landscapes, ECB damage to maize appeared unrelated to land use. Indeed, our stable carbon isotope analysis shows that one critical difference in the life histories of the two insects is host utilization: WCR utilized non-maize hosts (0%) at a lower rate than ECB (11%). However, management for both pests was consistently related to land use: less transgenic Bt maize and less insecticide is used per maize hectare in U. S. states with less maize. Consistent with field observations, our model predicts that landscape diversification results in reduced insecticide use and suggests that specialist pests are more affected by land-use changes than generalists. The model further predicts that insects with high reproductive rates are less sensitive to land-use change than insects with low reproductive rates and that dispersal distance is not an important factor regulating densities of highly dispersive insect pests in agricultural landscapes. While our study suggests that landscape diversification may not suppress all pests, it also suggests that diverse agricultural landscapes are correlated with consistently lower pesticide usage.

• 出版日期2011-12