Theoretical models for predicting timing and size of Heliothis spp. populations have been developed. Typically, a representative seasonal Heliothis population model uses early season field populations (adults or immature stages such as eggs or larvae) to forecast timing and size of later potentially damaging pest populations. Recent developments in pheromone identification and design of efficient pheromone traps have provided an excellent tool for measuring early season Heliothis adult numbers. Pheromone trap catches have been used in Southeast Arkansas as input to a Heliothis population model, MOTHZV, along with appropriate climate and crop phenology to predict the timing of future generations. These predictions along with pheromone trap catchs have proved to be a useful aid in making Heliothis management decisions in cotton production.