Integration of Insect-Resistant Genetically Modified Crops within IPM Programs

Abstract

Although host plant resistance has long been an important insect management tactic, its wide-spread use has been constrained by the limited availability of elite cultivars possessing high levels of resistance to key pest species. The application of recombinant DNA technology to genetically engineer insect-resistant crop plants has provided a way to eliminate this constraint and make host plant resistance a prominent component of integrated pest management (IPM) in major cropping systems world-wide. It is within the framework of IPM, rather than as a stand-alone insect control measure, that insect-resistant GM crops have the greatest potential to contribute to the establishment of sustainable crop protection systems. This chapter reviews the defining elements of IPM and examines the attributes of insect-resistant GM crops as IPM tools. Insect-resistant GM crops available to date, like their counterparts developed through conventional plant breeding, are proving to be safe, effective and easy to use insect suppression tools that are compatible with other IPM tactics, including cultural and chemical controls and the conservation of natural enemies as important agents of biological control. Because of their high level of efficacy against the key pest species that they target, GM Bt cotton and Bt maize varieties expressing cry genes derived from Bacillus thuringiensis (Bt) have been widely adopted and have led to significant reductions in insecticide use. Experience in Bt cotton has revealed the potential for reductions in insecticide use to be accompanied by the emergence of secondary pests and the need to adjust the pest management systems to address these “new” pests. Emphasis on the importance of resistance management to mitigate selection for pest adaptation to Bt crops has elevated the role of resistance management to a position of fundamental importance in the implementation of IPM.