Development of insect resistance to biopesticides

Abstract

Resistance to a number of different microorganisms has been documented in wild insect populations and deliberately induced in laboratory populations and domesticated insects. In recent years, rapid progress in introduction of toxin genes from insecticidal bacilli into-agricultural crops has raised concern that resistance to insecticidal bacteria may reduce the usefulness of these valuable microbial control agents. Mechanisms which have been implicated in resistance of insects to pathogens include changes in behavior, cuticle, and midgut cell turnover, reduced binding affinity of midgut proteins, and maturation immunity. Development of resistance to pathogens, particularly to those which do not act by means of a toxin, is expected to be of a different nature than resistance to chemical insecticides, and may proceed more slowly.