As part of a 3-yr, ARS Pilot Test, field studies were conducted at 3 geographical locations to determine the technical feasibility of using pheromone trap captures of Heliothis zea (Boddie) and H. virescens (F.) to predict field populations of these insects infesting cotton. Four Texas wire cone pheromone traps were operated for each species in each of five ca. 8 ha cotton fields in Burleson and Brazos counties during 1987 (May to Sept.). Egg populations were collected from twenty 2-m row samples, and larvae hatching from eggs were reared to determine species. Nocturnal adults were sampled using sweep nets. The timing of peak populations of H. zea captured in traps synchronized with peak egg populations in the field. Few H. zea eggs were obtained outside the single peak in July. Heliothis vireacens captures in pheromone traps followed a similar synchronized pattern fluctuating as did the egg populations; and this relationship was sustained until cotton was defoliated prior to harvest. Numbers of nocturnal adults of H. zea and H. virescens collected also synchronized with egg populations on cotton.