They found that toxin-resistant larvae of the Diamondback Moth developed faster and had a greater pupal weight in the presence of the toxin. This could be a genetic effect, linked indirectly to the presence of a resistance allele but more simply, could be due to resistant insects enhancing their ability to survive and digest the toxin. The present results are of particular interest because of the widespread use of crops expressing the toxin.
These crops could, therefore, have unforeseen nutritionally favourable effects, increasing the fitness of resistant insect populations. Biochemical studies are required to confirm such nutritional effects of Cry toxins on resistant insects.
Ecology Letters