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Submitted to: Information Systems for Biotechnology News Report
Publication Type: Research Notes Publication Acceptance Date: 12/1/2009 Publication Date: 12/18/2009 Citation: Naranjo, S. E. 2009. Bt Crops and Invertebrate Non-target Effects – Revisited. ISB (Information System on Biotechnology) New Report Interpretive Summary: Crops that have been transgenically engineered for resistance to select insect pests by the use of genes from a common soil bacteria (Bacillus thuringiensis) were grown on about 42 million hectares in 20 countries in 2007. Debate continues on the environmental risk of these crops. This short article summarizes a recent peer-reviewed paper that examined, in part, invertebrate non-target effects of Bt crops (cotton, eggplant, maize, potato and rice) using meta-analyses. Meta-analysis is a means of quantitatively combining the results from multiple studies to arrive at robust and statistically powerful interpretations of the data. Analyses revealed that the pattern and extent of impact varies in relation to taxonomy, ecological or anthropomorphic guild, route of exposure, and the non-Bt control against which effects are gauged. Hazards identified in the laboratory may not always manifest in the field and the minor negative effects of Bt crops demonstrated in the field pale in comparison to alternative pest suppression measures based on insecticides. In general, Bt crops appear to pose negligible risk to non-target invertebrates and have been associated with large reductions in insecticide use. Technical Abstract: Crops that have been transgenically engineered for resistance to select insect pests by the use of genes from a common soil bacteria (Bacillus thuringiensis) were grown on about 42 million hectares in 20 countries in 2007. Debate continues on the environmental risk of these crops. This short article summarizes a recent peer-reviewed paper that examined, in part, invertebrate non-target effects of Bt crops (cotton, eggplant, maize, potato and rice) using meta-analyses. Meta-analysis is a means of quantitatively combining the results from multiple studies to arrive at robust and statistically powerful interpretations of the data. Analyses revealed that the pattern and extent of impact varies in relation to taxonomy, ecological or anthropomorphic guild, route of exposure, and the non-Bt control against which effects are gauged. Hazards identified in the laboratory may not always manifest in the field and the minor negative effects of Bt crops demonstrated in the field pale in comparison to alternative pest suppression measures based on insecticides. In general, Bt crops appear to pose negligible risk to non-target invertebrates and have been associated with large reductions in insecticide use. |
