10 th International Working Conference on Stored Product Protection Julius-Kühn-Archiv, 425, 2010 977 The potential of transgenic legumes in integrated bruchid management: assessing the impact on bruchid parasitoids Lüthi, C.*#, Álvarez-Alfageme, F., Romeis, J. Agroscope Reckenholz-Tänikon Research Station ART, Reckenholzstrasse 191, 8046 Zurich, Switzerland. Email: christoph.luethi@art.admin.ch * Corresponding author # Presenting author DOI: 10.5073/jka.2010.425.167.251 Abstract Leguminous seeds are an important staple food and source of nutrition in many countries. Bruchid beetles (Coleoptera: Bruchidae) are responsible for the greatest post-harvest losses to stored legumes. A powerful strategy to control bruchid infestations is the combination of plant resistance factors and biological control provided by parasitoids. Potent resistance factors are α-amylase inhibitors (αAI) which inhibit the starch metabolism in sensitive insects. Genetic engineering has been used to transfer αAI-1 from the common bean (Phaseolus vulgaris) to other leguminous plants which are subsequently protected from the attack by several bruchid species. However, there are concerns regarding the effects that the expressed insecticidal protein might have on non-target organisms. Here, we present an approach to assess the impact of αAI-1 genetically modified legumes on bruchid parasitoids. Keywords: Risk assessment, Genetically modified plants, Non-target organisms; α-amylase inhibitor; αAI-1 1. Introduction Legume seeds are an important source of nutrition for both humans and livestock. Their seeds are rich in proteins, carbohydrates and lipids, and they can be stored over extended periods. Additionally, the nitrogen-fixing abilities of the plants are important for the management of soil fertility. All these properties match perfectly with the requirements of small-scale, low-income farmers in developing countries. Bruchid beetles (Coleoptera: Bruchidae) are responsible for the largest post-harvest losses to stored seeds, directly through consumption of the resource and, secondarily, through the qualitative deterioration of the commodity or the reduced stock viability. The females lay their eggs on the seed surface and the larvae burrow into the seed, where they feed and complete their development (Southgate, 1979). The beetles usually continue to multiply during seed storage, which can lead to extensive or even total losses, especially if the seeds are stored for long periods. Surface and fumigant chemical applications are thought to be the most effective methods for managing bruchid infestations. However, prohibitive costs, which limit their application to large scale or extended storage, and the risks of adverse secondary effects from such treatments, have driven the exploration of alternative strategies to manage bruchid infestations. These include biological control ( Sanon et al., 1998; Gauthier et al., 1999; Schmale et al., 2006) and plant resistance factors ( Ignacimuthu et al., 2000; Schmale et al., 2003; Appleby and Credland, 2004). A crop protection tool with high potential for small-scale farmers is genetic engineering. Although the largest areas of genetically modified (GM) crop production have been in industrial countries, it’s the small-scale farmers in developing countries that might benefit the most from this technology ( Wambugu, 1999; Thomson, 2008). In 2008, 90% of the farmers planting GM crops were in developing countries (James, 2008). To date, all commercially cultivated insect-resistant GM crops are expressing Cry proteins derived from the soil bacterium Bacillus thuringiensis (Berliner) (so called Bt crops). The potential of insects to evolve resistance against the deployed Bt Cry toxins, their narrow spectrum of activity and the risk of infringing existing patents have driven the development of alternative insecticidal traits for genetic engineering, including inhibitors of digestive enzymes (Malone et al., 2008).