Developing Bisexual Attract-and-Kill for Polyphagous Insects: Ecological Rationale versus Pragmatics

We discuss the principles of bisexual attract-and-kill, in which females as well as males are targeted with an attractant, such as a blend of plant volatiles, combined with a toxicant. While the advantages of this strategy have been apparent for over a century, there are few products available to farmers for inclusion in integrated pest management schemes. We describe the development, registration, and commercialization of one such product, Magnet®, which was targeted against 'Helicoverpa armigera' and 'H. punctigera' in Australian cotton. We advocate an empirical rather than theoretical approach to selecting and blending plant volatiles for such products, and emphasise the importance of field studies on ecologically realistic scales of time and space. The properties required of insecticide partners also are discussed. We describe the studies that were necessary to provide data for registration of the Magnet® product. These included evidence of efficacy, including local and area-wide impacts on the target pest, non-target impacts, and safety for consumers and applicators. In the decade required for commercial development, the target market for Magnet® has been greatly reduced by the widespread adoption of transgenic insect-resistant cotton in Australia.We discuss potential applications in resistance management for transgenic cotton, and for other pests in cotton and other crops.