Area-wide effects of a plant volatile-based attract and kill formulation against 'Helicoverpa armigera' and 'H. punctigera' in Australia

Abstract

Magnet® is an attract-and-kill formulation based on plant volatiles which is currently undergoing product evaluation trials on about 20,000 ha of cotton, and smaller areas of other crops, in Australia. It is based on a blend of five plant volatiles, previously shown in olfactometer studies to be attractive to both sexes of 'Helicoverpa armigera' and 'Helicoverpa punctigera'. These noctuid moths are key pests of cotton, and also affect many other crops, in Australia. This presentation will discuss the area-wide effects of treating individual fields, or contiguous areas of cotton, with Magnet® containing small quantities of the insecticides methomyl and thiodicarb. Methods used to estimate the numbers of moths killed, and simple models to predict the impacts on oviposition, will be described. 'Helicoverpa' spp. moths are extensively mobile within and between fields, and treated areas appear to act as population sinks, over distances of several km. Substantial reductions in oviposition can be obtained, not only in treated fields but in fields some distance away. Magnet® is applied to less than 2% of the area of treated fields, thus allowing beneficial predators and parasitoids to survive in the larger untreated area of the field. Attract-and-kill with formulations based on plant volatiles offers considerable promise as a component of area-wide integrated pest management for 'Helicoverpa' spp. Potential applications in resistance management for transgenic crops will also be discussed.