为进一步揭示转Bt基因抗虫棉对中华草蛉Chrysopa sinica (Tjeder)生物学特性的影响，以泗棉3号和GK12为材料，以棉蚜为猎物，研究了转基因抗虫棉对中华草蛉存活率、发育历期和繁殖力的影响。结果表明，转基因抗虫棉对中华草蛉幼虫期存活率、幼虫发育历期、蛹发育历期与对照差异均不显著；对成虫寿命、体重以及雌虫繁殖力也无显著差异。表明转Bt抗虫棉对中华草蛉的生物学特性影响较小。

opulation dynamics of two predatory beetles, Propylaea japonica (Thunberg) and Harmonia axyridis (Pallas) were surveyed in agricultural landscapes composed of cotton and maize in North China. Crop composition (cotton and maize) was found to significantly affect population densities of the beetles in this agricultural landscape system. Population densities of both beetles in maize patches were higher than in cotton patches, and adults of both species prefer to inhabit maize plants. The population densities of the two species varied through time in the cotton patches, with more adults of P. japonica in the earlier and middle stages and fewer in the later stage, and fewer adults of H. axyridis in the earlier and middle stages and more in the later stage. These results suggest that maize can serve as a habitat or refuge for predatory beetles and its presence may enhance biological control of insect pests in cotton. The proportion of maize patches in the agricultural landscape significantly affected adult densities of these two predatory beetles. This suggests that habitat management with a suitable ratio and spatial arrangement of cotton and maize may enhance the biological control of pest insects.