A large number of transgenic crop varieties expressing the Bt (Bacillus thuringiensis) insecticidal proteins have been commercialized in 13 countries since 1996. Although the use of these insect-resistant Bt crops can increase crop quality and yields, concerns remain about the potential negative effects of such crops on ecosystems. Transgenic soybean containing cry1Ac gene have been developed to control Lepidopteran pests of soybean and we aimed to investigate whether this soybean could affect non-target arthropods, which play a major role in ecological functions in agricultural ecosystems. In the present study, we first measured the levels of Cry1Ac protein in Bt soybean at different growth stages of soybean and then we compared the community structure of arthropods occurred in fields of transgenic and wild-type soybean. The levels of Cry1Ac protein in transgenic soybean leaves ranged from 252.9 to 604.5 μg g-1 DW. Multivariate analyses (PerMANOVA and NMDS) showed that the composition of the non-target arthropod community was affected by sampling date but not by soybean genotype. These results suggest that transgenic soybean expressing Cry1Ac protein may not adversely affect such non-target arthropod communities.

• Young-Joong Kim(Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Entomology program, Department of Agricultural Biotechnology, Seoul National University)
• Joon-Ho Lee(Entomology program, Department of Agricultural Biotechnology, Seoul National University, Research Institute of Agriculture and Life Sciences, Seoul National University)
• Young Soo Chung(Department of Genetic Engineering, Dong-A University)
• Chang-Gi Kim(Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology)