Plantings of cotton bioengineered to produce its own insecticide against bollworms, a major cause of crop failure, sustained little bollworm damage until this year  This year the plantings are being seriously damaged by bollworms  Bollworms, however, are not necessarily developing resistance to the cotton' s insecticide  Bollworms breed on corn, and last year more corn than usual was planted throughout cotton-growing regions
So it is likely that the cotton is simply being overwhelmed by corn-bred bollworms
Whether other crops that have been bioengineered to produce their own insecticide successfully resist the pests against which the insecticide was to protect them