Science: No effects of Bacillus thuringiensis maize on non-target organisms: Hollande "Lets ban it then to win votes"

No effects of Bacillus thuringiensis maize on nontarget organisms in the field in southern Europe: a meta-analysis of 26 arthropod taxa.

Maize with the insecticidal properties of the entomopathogenic bacterium Bacillus thuringiensis Berliner, known as Btmaize, has been sown in Europe since 1998. For several years, EU and Spanish regulations have required laboratory and field trials to assess risks of genetically modified crops for nontarget organisms prior to their authorization. Thirteenfield trials were conducted in Spain to measure the effects of Bt maize on a broad range of arthropod taxa; no effectswere found in accordance with most literature records. However, statistical analyses of single trials rarely have the statistical power to detect low effect sizes if they do not have a sufficient sample size. When sample size is low, meta-analysis may improve statistical power by combining several trials and assuming a common measure of effect size. Here we perform a meta-analysis of the results of 13 independent field trials conducted in Spain in which effects of single or stacked Bt traits on several arthropod taxa were measured with no significant results. Since the taxa included in each single trial were not the same for all trials, for the meta-analysis we 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 dramatically 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 themeta-analysis than the best recorded in the 13 single trials. This finding reinforces the conclusion that Bt maize has no effect on the most common herbivore, predatory and parasitoid arthropods found in the maize ecosystems of southernEurope.

Transgenic Res. 2013 Aug 2.
Comas C, Lumbierres B, Pons X, Albajes R.
Source Department of Mathematics, Agrotecnio Center, Universitat de Lleida, Catalonia, Spain,

@ No effects of Bacillus thuringiensis maize on... [Transgenic Res. 2013] - PubMed - NCBI:

Previous post:

... "Hollande said the ban on GM crops was in place "not because we refuse progress, but in the name of progress."

"We cannot accept that a product -- corn -- have bad consequences on other produce," he added, stressing that it would however be necessary to "secure this decision legally, at a national level and especially at a European level."...