Resistance of Helicoverpa armigera to traditional cotton insecticides such as synthetic pyrethroids and endosulfan is a major problem for the Australian Cotton Industry. This problem is complicated by the presence of Helicoverpa punctigera which has not shown resistance to any chemical insecticides, to date.

In an effort to contain this resistance problem, the Australian Cotton Industry has implemented a successful Resistance Management Strategy over the past 10 seasons. The success of this strategy depends on knowing when Helicoverpa armigera are present, and what proportion of the population is armigera.

Prior to the advent of the LepTon Test, the only way of identifying the species present was to grow the larvae out to the third instar. This took around ten days.