The community of herbivorous arthropods as an indicator for biological control function in the Post Market Environmental Monitoring of the cultivation of stacked Bt maize

摘要

In field experiments on the potential impacts of the genetically engineered Bt maize events MON 810, MON 88017, and MON 89034 x MON 88017, data were gathered on a diverse range of non-target organisms (NTO). These experiments were performed at different trial locations since 2001. Surveying herbivores serves two purposes: (i) to assess direct effects on these NTO, and (ii) indirectly analyse disturbances in the biological control function of natural enemies (Sanvido et al., 2009). Herbivores of interest for this approach should be exposed to the Bt proteins, representative for the maize biocoenosis, and of considerable densities using standardised methods. Plant bugs (Heteroptera: Miridae), plant- and leafhoppers (Auchenorrhyncha), and flowervisiting arthropods such as thrips (Thysanoptera) were chosen as potential canditate groups. To evaluate the abundances of these insects, the herb layer was sampled using sticky traps and sweep netting. Maize panicles were sampled during anthesis. The data demonstrate that there is a prevalent community of herbivores in maize, dominated by a few species that can be surveyed over the whole growing season using the methods employed.