Original aims of the project are listed below: (i) To continue evaluation of the insect resistance of a range of cotton genotypes, including lines derived from crosses of promising HPR varieties with high yielding commercial varieties, including combinations with transgenic Bt lines (ii) To evaluate levels of aphid and mirid resistance in a broad range of genotypes under conditions where high densities of these pests will be induced (iii) To quantify biochemical changes in cotton genotypes associated with efficacy of transgenic cotton and the compensatory ability of different genotypes (iv) To identify the potential for induced defensive response to be used in selective breeding or to interfere with the efficacy of IPM tools such as virus sprays.