Abstract:

The thirdinstar larvae of the cotton bollworm, Helicoverpa armigera (Hübner), were raised to adult with artificial diet containing Bt Cry1Ac toxin at 40%－50% lethal dose. Electroantennogram (EAG) responses were recorded for those survival male moths and untreated moths. The results indicated that EAG values of Bt toxin treated males to Z9-16:Ald, Z11-16:Ald and their binary mixture （Z11-16:Ald∶Z9-16:Ald=97∶3） were all higher than those of controls, and that differences of the EAG values between treatments and controls became greater as the concentration of the sex pheromone components increased. These results were meaningful in evaluation and implementation of the “refuge" strategy used to postpone the Bt cotton resistance by the cotton bollworm.

Key words: Bt toxin, Helicoverpa armigera, sex pheromone, EAG response