Sterile female pink bollworm moths,Pectinophora gossypiella(Saunders). originating from a mass-rearing facility and intercepted en route to be air-dropped over the San Joaquin Valley of California, emitted amounts and ratios of pheromone components that were not significantly different from field-collected females. Sterile males from the same shipments were as successful as field-collected males in mating with either sterile or field collected females. However, sterile males spent significantly more time during courtship to secure copulations. Field-collected females mated at significantly lower frequencies than sterile females, most likely because of laboratory conditions that were not optimal to induce calling behavior. These results indicate that, for the most part, even after the rigors of mass rearing and shipment, sterile males and females are sexually competent and that much of the benefit of sterile pink bollworm releases may come from the sterile females. Sterile males might, under some conditions. be outcompeted by field males were they to court a calling female at approximately the same time.