Cereal leaf beetle spatial dynamics: Simulations with a random diffusion model

Abstract

An existing model simulating the spatial dynamics of the cereal leaf beetle (CLB), Oulema melanopus, was used to examine the consequences of the hypothesis that dispersal by this species is a random diffusion process. The effects of spatial and temporal manipulations of the environment on the distribution and abundance of beetles in a regional crop system were determined. Simulation experiments included converting all winter wheat to a CLB-resistant variety, altering the syncrony of insect emergence and the phenologies of winter and spring host crops, varying the absolute and relative areas of crops planted, and making systematic changes in field size, shape and location. Results highlight the importance of the interfield environment as a reservoir of dispersing insects, and the sensitivity of pest density to the synchrony of winter and spring crop growth. Cultural management practices are suggested that may reduce CLB density in cereal crops, especially if they are coordinated on a regional scale.