The last year has seen a growing public concern over the use of chemical pesticides for the control of insect pests in cotton at a time when the Cotton Industry itself is still facing the real risk that these chemical pesticides will become ineffective due to the development of resistance by the insects. Improvements in the natural tolerance of cotton varieties to insect attack, by whatever means, should satisfy both parties by, one the one hand, reducing the need for pesticide application and its consequent deleterious impacts on the environment, and, on the other, by providing another weapon in the arsenal for the control of insects by an Integrated Pest Management strategy. One strategy that has been suggested, and currently under assessment by the breeders at Narrabri, is to increase cotton's Host Plant Resistance to Heliothis by breeding for the production of allelochemicals that the insects will find unpalatable. While this approach may be successful, the yield and quality penalties of producing these chemicals remains uncertain. We have adopted an alternative approach that will use genetic engineering to introduce into cotton genes for the production of insecticidal proteins that will be toxic to Heliothis larvae, but hopefully with little yield or quality penalty since the expression of these genes can be very tightly regulated to the cotton tissues at most risk to insect attack.