Field studies were carried out to evaluate the effect of two transgenic cotton varieties (SGK321 carrying Cry1A + CpTI and DP99B carrying Cry1Ac) and the conventional variety (shiyuian321-parental line of SGK321) to cotton spider mites Tetranychus spp.

• 2002-2004年,在冀南棉区系统调查了Bt棉品种DP99B(转Cry1Ac基因)和对棉叶螨发生的影响。 2002年,试验的Bt棉品种为SGK321(转Cry1Ac+CpTl基因);