An assessment of environmental risk of Bt-maize on rove beetle communities

An environmental risk assessment related to the genetically modified crops still needs to be studied. In the non-target organisms, rove beetles seem to be well-chosen arthropods for this purpose. Rove beetle abundance and species diversity were studied in the first large-scale Bt-maize experiment in the south part of Poland for over two years to determine the impact of Bt-maize in comparison to conventional varieties. A genetically engineered Bt-maize variety (DKC 3421 Yield Gard®, event MON 810) and its near-isogenic DKC 3420 were cultivated at two locations. Additionally, two non-Bt varieties sprayed with a lambda-cyhalothrin insecticide were also included for comparative analysis. The results show no significant effects on rove beetle abundance and diversity patterns of the Bt-maize and the nearby isolines. In one locality the mean number of individuals and Simpson dominance was even higher in Bt-maize compared to one reference variety. The Canonical Correspondence Analysis showed rather variety-dependent effects of the rove beetle community. To conclude, considering the abundance and diversity of studied insects, there is no environmental risk arising from Bt-maize cultivation.