Management of pesticide resistance based on heterogeneous field management and type of pests

We developed a simple simulation model for the management of pesticide resistance in insect pests. The model is based on the assumption of a one-locus, two-allele (the wild and resistant types) genetic structure and also assumes the prevalence of a mosaic environment in the crop field where some fields are sprayed with focal pesticide, while others are not. Using this simulation model, the order of life events (e.g., pesticide selection, mating, and migration), dominance level of resistance, cost of acquiring the resistance, initial resistance allele ratio, and patch selection ability were evaluated.

The simulations demonstrated retarded resistance development when the resistance allele was perfectly recessive and migration took place before mating. On the other hand, imperfect dominance of the wild allele can significantly accelerate resistance development. Every pest type rapidly degraded the pesticides when the pesticide application did not kill all the wild types. Based on these simulation results, we conclude that resistance development is largely influenced by the type of pests, pesticide toxicity, and degree of dominance of the resistance allele. It is critical to ascertain the life history of the target pest, pesticide toxicology, and heredity of the resistance allele in the pest before application of a new pesticide.