In January 1983, pyrethroids failed to give satisfactory field control of Heliothis (Helicoverpa armigera (Hubner) at Emerald in central Queensland. Prior to that, as in the USA (Riley 1989), they had been "heralded as miracle insecticides" as they replaced the resistance prone and environmentally liable organochlorines, cyclodienes and organophosphates (Morton & Collins 1989). When they were introduced commercially in the late 1970's, they had many benefits over what was then available. They were very cost effective at extraordinarily low rates on a broad range of agricultural and public health pests, had no residue problems, were safe to mammals, had low environmental impact and were immobile in the soil (Elliott 1989). Indeed, they were regarded as the almost perfect insecticide (Leahey 1985). In fact, by 1986, their popularity was such that they accounted for around 25%, of all insecticides used in agriculture and public health (Jackson 1989, Hirano 1989). They were particularly favoured in cotton because of their contact mode of action and good efficacy against previously resistant pests and by the mid 1980's accounted for 49%", of the world cotton insecticides market (Walkinson 1989, Riley 1989). So when the breakdown at Emerald was clearly shown to be due to the development of resistance (Gunning et al 1984), there was no disguising the concern of the Australian cotton industry in particular, but also the other field crop industries in which H. armigera was a key pest. Within 6 months of these reported field failures, a strategy aimed at containing the resistance problem, had been formulated and ratified for use in the following season, by all parties concerned (Forrester 1990)