The industry is entering a critical period in managing resistance to Bt-cotton.

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.

The Australian cotton industry depends heavily on genetically engineered Bt cotton (currently in the form of Bollgard II®) which provides resistance to the key pests of cotton, larvae of the moths Helicoverpa armigera

Transgenic (Bt) cotton has provided major benefits for the Australia cotton industry (e.g. control of Helicoverpa and reduced pesticide use), but the possibility of Bt resistance in these insects is a major threat.

Even though large scale planting of Bt cotton started a decade ago, consequences on a landscape-scale have hardly been studied. Helicoverpa armigera and H.