Field trial examining the use of Bacillus thuringiensis (Bt) foliar sprays on transgenic and conventional cotton varieties showed various levels of Helicoverpa control and impacts on beneficial insects.

Key factors in managing transgenic Bt cottons for the future are to have an effective

resistance management strategy. An essential component of any such strategy is to

The susceptibility to Bt toxins in Australian field populations of Helicoverpa armigera and Helicoverpa punctigera has been monitored at the Australian Cotton Research Institute since 1993 (Forrester and Bird 1996).

What were the Project Objectives 1) Calibrate thiodicarb laboratory discriminating dose data w ith levels of control of Helicoverpa in the field.

New insecticide technology is needed in the Australian cotton production system to reduce reliance on old chemical groups and to maintain profitability.