Effects of GM Crops on Non-target Organisms

Abstract

Genetically modified (GM) crops have now been part of the agricultural landscape for 17 years and have become important tools in crop production and Integrated Pest Management (IPM) in many countries. There has been considerable research addressing many associated issues including environmental and food safety, as well as economic and social impacts. In particular, extensive laboratory and field research has been generated relative to the assessment of non-target effect in transgenic Bt crops that produce the insecticidal proteins of a ubiquitous bacterium, Bacillus thuringeinsis. This body of evidence and the quantitative and qualitative syntheses of the data through meta-analysis and other compilations generally indicate a lack of direct impacts of Bt crops on non-target macro-invertebrates. The data also clearly show that Bt crops are much safer to non-target organisms than the alternative use of traditional insecticides for control of the pests targeted by the Bt proteins. Some indirect effects on arthropod natural enemies associated with reduced abundance or quality of Bt target herbivores have been shown, but the ramifications of these effects are unclear. As one tactic in the IPM toolbox, Bt crops have contributed to large reductions in insecticide use. While reduced insecticide use may be involved in precipitating new pest problems in Bt crops it also has broadened opportunities for deployment of another IPM tactic, biological control.