The paper reviews the various findings in the economics literature on the efficiency of cotton defoliation strategies. The discussion then focuses on the potential cost savings of adding sub-lethal insecticides with routine defoliant sprays in the Texas Lower Rio Grande Valley. The evaluation of economic benefits is complicated by time/space dimensions, but the small marginal cost of diapause insecticides may justify including them in defoliation sprays, provided that such treatments are uniformly applied to a large area. The latter condition is necessary to enable physical, technological substitution of in-season weevil sprays for cheaper diapause sprays.