As part of a 3-year, 3-location ARS Pilot Test on sex pheromone trap calibration for Heliothis spp., data were collected in 1987-89 in cotton fields close to College Station, TX on the relationship between captures in traps and field populations. Four wire cone traps for each species, H. zea and H. virescens, were operated and checked daily in 5 fields in 2.987, 7 fields in 1988, and 5 fields in 1989. These fields were irrigated and dryland producer cotton that received all conventional production practices including insecticide applications. An effort was made to determine egg densities in each field at least biweekly; however, reentry periods after insecticide applications frequently and inclement weather occasionally prevented sampling at the desired frequency. Adults in selected fields were sampled at night as conditions permitted and the number and sex of both species and the reproductive condition of the females were determined. These data were evaluated for the direct use of numbers of males captured in the traps in the management of these 2 important cotton pests. Qualitatively, trends in the species composition of eggs obtained in the field were reflected in the percent of each species captured in the pheromone traps and increases in oviposition of each species were frequently associated with increases in captures of the appropriate species. Quantitatively, no simple relationship between numbers of males captured in the pheromone traps and egg densities of each species was apparent for all 3 years for both the timing and size of peaks. More intensive analyses on the effect of biotic and abiotic factors on adult moth activity relating to response to and capture in pheromone traps, mating and oviposition will be required if less apparent and more complex relationships which will require a modelling approach are to be identified.