An insecticide resistance management (IRM) strategy was introduced into the summer rainfall cropping areas of eastern Australia in the 1983/84 season. The aims of this IRM strategy were to manage pyrethroid and endosulfan resistance problems in Helicoverpa armigera (Hubner), formerly Heliothis armigera (Hubner), and to avoid any possible future problems with organophosphate or carbamate resistance. An alternation strategy was adopted which was based on the rotation of unrelated chemical groups on a per generation basis, along with a strong recommendation for the use of ovicidal mixtures. These chemical countermeasures were then incorporated into an acceptable integrated pest management (IPM) programme. The voluntary restrictions were applied to all crops susceptible to H. armigera. They were even applied to other co-incident pest species on these hosts, such as sorghum midge Contarinia sorghicola (Coquillet) (Diptera: Cecidomyiidae), as it was shown that pyrethroids applied to flowering sorghum for midge control caused selective mortality of co-incident H. armigera larvae and resulted in differential selection for resistance. The demonstration of the independence of the endosulfan and pyrethroid resistance mechanisms vindicated the sequential use of these two groups in Stages I and II of the IRM strategy, respectively