|Tuat, Nguyen van|
Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 1/21/2004
Publication Date: 5/1/2006
Citation: de Faria, M. R., J. G. Lundgren, E. M. G. Fontes, O. A. Fernandez, F. Schmidt, and N. Van Tuat, and D. A. Andow. 2006. Chapter 8: Assessing the impact of Bt cotton on generalist arthropod predators. Pages 175-199, In: "Environmental Risk Assessment of Genetically Modified Organisms Volume 2: A Case Study of Bt Cotton in Brazil" (A. Hilbeck, D. A. Andow, and E. M. G. Fontes, eds.). CABI Publishing, Oxfordshire, UK. Interpretive Summary: The GMO Guidelines Project is an international effort to develop a set of transparent guidelines that can assess the environmental safety of GM crops. The focus of this book chapter is to synthesize a workshop conducted in Brazil on evaluating the risk of GM cotton to predatory insects and spiders. These predators are important beneficial components of cropland, and so it is important that GM cotton is compatible with these organisms. The chapter outlines the methods that we recommend to evaluate the ecological safety of GM cotton to predators, and these methods involve the ecology and behavior of the predators, as well as a comprehensive examination of previous literature. One of the major conclusions of this research is that we need to have a much better understanding of the biology of beneficial insects before experimental recommendations can be made to assess the full impact of GM cotton.
Technical Abstract: This research was conducted as part of the GMO Guidelines Project, an international effort to develop a set of transparent guidelines that can assess the environmental safety of GM crops. The focus of this chapter was on the potential risk that the cultivation of Bt cotton might pose on the natural biocontrol function of predators. We carried out a partial exposure and hazard analysis as an example of the process for the best known groups – the lacewings (Chrysopidae) and ladybird beetles (Coccinellidae). Going through this process also revealed knowledge gaps, such as Bt protein expression in nectar and phloem, and whether Homoptera take it up, (thereby possibly exposing the predator life cycle stages that feed on Homoptera and their honeydew), but these gaps can be filled with relatively simple experiments. We generally agreed that the exposure matrix was useful and helpful in making decisions to prioritise questions for research, and can be used in an iterative way once information is obtained from the suggested exposure assays. The methodology used has enabled the authors to identify significant gaps of knowledge that need to be filled before a full risk assessment can be carried out, and moreover, to prioritize the most important knowledge gaps. Many of the predators could only be considered as whole families in this chapter, but we recommend repeating the selection process once additional baseline knowledge about the cotton agro-ecosystem in each region, season and crop production system likely to include Bt cotton is available. For instance, information on species presence and prey preference on cotton for the Chrysopidae, Coccinellidae, Lycosidae and Formicidae would be particularly useful. We recommend involving taxonomic experts before selecting a focal species in the Chrysopidae and Coccinellidae, as cryptic species complexes occur in both of these groups.