Meta-analysis Shows Bt Maize Does Not Affect NTOs

A meta-analysis of 13 independent Bt maize field trials in Spain were performed by researchers from Universitat de Lleida to assess the risk of the crop on non-target organisms (NTO) using combined samples and results. Since the taxa included in each single trial were not the same for all trials, the researchers selected only those taxa recorded in a minimum of six trials, resulting finally in 7, 7, and 12 taxa analyzed in visual counts, pitfall traps and yellow sticky traps, respectively.

In comparison with single trial analysis, meta-analysis significantly increased the detectability of treatment effects for most of the taxa regardless of the sampling technique; of the 26 taxa analyzed, only three showed poorer detectability in the meta-analysis than the best recorded in the 13 single trials. The results of this study support the conclusion that Bt maize has no effect on the most common herbivore, predatory, and parasitoid arthropods found in the maize ecosystems of southern Europe.

The abstract is available at Transgenic Research: http://link.springer.com/article/10.1007/s11248-013-9737-0.