Impacts of Bt cotton on host selection behavior of Helicoverpa armigera larvae;

Three non-hybrid and two hybrid Bt cotton cultivars developed in Shandong province,as well as their control cultivar 33B,were grown and comparatively studied in 2002 and 2004.

Based on the survey in 1997, a further systematic survey was made in a transgenic Bt cotton field and two non-transgenic cotton fields (one with IPM, one with chemical control) in Nanpi county, Hebei province, in 1998.

Effect on the biological habit of ballworm after planting Bt transgenic cotton in Xinjiang;

Resistance of two Bt transgenic cotton lines (GK 19 and BG 1560) to cotton bollworm (Helicoverpa armigera) was assessed through bioassay and field investigation.