Genetic basis for Bt resistance

Much like antibiotic-resistant strains of bacteria, the emergence of pesticide-resistant insects is an ever-present problem. Research published in Science suggests that in the lab, the European corn borer develops resistance to Bacillus thuringiensis (Bt) endotoxins as an incompletely dominant genetic trait, as opposed to other insects where resistance appears to be genetically recessive.

If the results hold up in the field, they could affect the current resistance management strategy of planting Bt fields next to Bt-free corn, where the borers may reproduce without selective pressure to develop resistance. The success of these refuge fields hinges on a recessive resistance trait. In the lab case, an insect with one copy of the mutant gene can express the trait...