Information about the frequency and intensity of immigration and emigration movements is essential for forecasting Heliothis infestation levels in crops, and thus for developing more efficient strategies for managing

Heliothis spp.

With current Australian cotton production around 1.25 million bales this equates to C.R.C. research expenditure of A$3.2 to 3.5 million per year - allowing for reserves, administration, etc. These C.R.C.

As major pests of cotton production, Heliothis spp. are of most concern to growers during the summer when they are active and damaging crops. Once autumn arrives and the crop is picked, Heliothis are soon forgotten.

The threat of resistance has been realised, and no doubt will continue to be realised in the future. What then is the cost once resistance has developed?