Insect-resistance of Transgenic Bt Cotton against Helicoverpa armigera

Indoor observations and analysis of different biological indicators of Helicoverpa armigera fed on conventional cotton and different varieties of Bt transgenic cotton during their growth and development were conducted.The results showed the impacts of transgenic Bt cotton on body weight and mortality of Helicoverpa armigera larva of different varieties were JK-1DB D16 Xinluzao 36. Compared with the control group, the pupation rate of larva fed on transgenic Bt cotton leaves, was reduced by 12.5%~30.0%, weight of pupation was decreased by 15.6%~41.9% and the emergence rate dropped by 5.5%~80%.