Aims: (i) to quantify the contribution of alternative host crops to the dynamics of Heliothis on cotton using an elemental analysis technique developed in a previous project. (ii) to study the colonisation of cotton crops by adults and subsequent development of populations using night vision devices, pheromone and light traps and direct sampling techniques. (iii) to quantify the catch efficiency of pheromone traps and factors affecting efficiency in cotton at different times of the season. (iv) to study patterns of local movement from discrete source crops, using mark-recapture, elemental analysis, night vision devices and trapping systems