Assessment of the potential impact of a Bt maize hybrid expressing Cry3Bb1 on ground beetles (Carabidae)

Abstract

The potential impact of a Bt maize hybrid expressing the coleopteran specific Cry3Bb1 on non-target organisms was assessed in a field release experiment. The study examined the relative abundance of ground beetles (Carabidae) in four maize varieties including the genetically engineered DKC 5143-Bt (event MON 88017), its near-isogenic line DKC 5143 and the two conventional varieties DK 315 and Benicia. Pitfall traps were used to collect the ground dwelling arthropods, which were analyzed to species level. Statistical comparisons showed no significant differences of ground beetle activity densities and diversity patterns between the Bt maize and the near isoline. The internal contents of the Bt protein Cry3Bb1 in ground beetles collected from the field were measured with ELISA. The Bt protein was found in 47% of the ground beetles sampled in Bt plots before the anthesis and in 66% of the individuals sampled after the beginning of maize anthesis.