Field surveys of insect populations in agroecosystems reveal low but significant levels of tolerance to Bacillus thuringiensis(Bt) toxins without mutational changes in resistance alleles.

The native budworm Helicoverpa punctigera is an important pest of field crops in Australia alongside the cotton bollworm Helicoverpa armigera, and both share a number of host plants. H.

In the Australian cotton industry, toxins produced by the soil bacterium Bacillus thuringiensis (Bt toxins) are utilized to control lepidopteran pests: Helicoverpa armigera (cotton bollworm) and H. punctigera.

Field work was conducted over the 1988/89 and 1989/90 cotton growing seasons in the Central Highlands of Queensland. Pheromone dispensers, specially formulated for P.

The Australian cotton industry is heavily dependent on chemical insecticides for pest control.