ABSTRACT
This chapter focuses on the potential for insects to develop resistance to an important recourse for bioengineered insecticides — Bacillus thuringiensis. It describes the history of insect resistance to B. thuringiensis, genetic and physiological mechanisms of resistance, and proposes strategies to delay or prevent resistance to B. thuringiensis-based products from occurring. Products based on B. thuringiensis are the most widely used biological insecticides. They are registered for the control of many economically important lepidopteran, coleopteran, and dipteran pests. Reports of field resistance or reduced efficacy to B. thuringiensis are few and restricted to situations where the insecticide was used intensively. Selection for resistance in the laboratory to B. thuringiensis has produced varying results depending on the bacterial products involved, that is, the insect species, and selection procedure. Study of mechanisms of resistance have centered on the effects of chemical insecticides.
