Abstract: Laboratory experiment s were carried out to study the survival and development of the Chinese green lacewing Chrysopa sinica and turtle ladybird Propylaea japonica feeding on cotton whitefly Bemisia tabaci on t ransgenic Bt cotton GK12 and NuCotn 33B. The parental line of GK12 , non-t rans-genic Simian-3 was used as cont rol. The mortality and development during immature period , adult body mass and sex ratio of C. si nica and P. japonica were measured. The result s showed that : ①B .tabaci on GK12 had no significant impact s on survival and development of immature C. si nica. It took
21. 3d for newly-hatched C. si nica to develop into adult , with a mortality of 40 % and sex ratio close to 1∶1. ②B . tabaci on NuCotn 33B negatively affected immature C. sinica. It s immature duration pro-longed to 24. 3d , with a mortality as high as 85 %. All adults developed f rom the tested larvae were females. ③B . tabaci on non2t ransgenic cotton plants was proved not suitable for larval survival of P.japonica and 86. 7 % larvae died. But B . tabaci on the two tested Bt cotton lines GK12 and NuCotn 33B caused only 53. 3 % and 26. 7 % larval mortality respectively , which were significantly lower than
that in the cont rol. ④ Feeding on B . tabaci on GK12 and NuCotn 33B , the immature duration of P.japonica was 15. 5d and 13. 9d ; and adult body mass was 4. 0mg and 4. 2mg respectively , showing no significant differences. However , larval mortality of P. japonica feeding on B . tabaci on GK12 and
NuCotn 33B differed significantly , B . tabaci on NuCotn 33B caused the lowest mortality.