Physiologically based demographics of Bt cotton-pest interactions

Predator longevity feeding on Bt intoxicated prey is decreased ca. 28% [Ponsard, S., Gutierrez, A.P., Mills, N.J., 2002. Effects of Bt-toxin in transgenic cotton on the adult longevity of four heteropteran predators. Environ. Entomol. 31, 1197-1205.] creating tradeoffs between the mortality caused by the toxin and that due to reduced predation. Despite reduced natural enemy efficacy, levels of susceptible pests (budworm) are reduced, while levels of Bt tolerant and immune pests (e.g. fall armyworm, Lygus) increase. The use of pesticide for supplementary control of tolerant pests in Bt cotton may further disrupts natural enemies and increase pest levels.