Ethephon and thidiazuron significantly reduced the number of green bolls and diapausing pink bollworm, Pectinophora gossypiella (Saunders), larvae in small plot (0.02 ac) tests when applied by September 6. Ethephon was effective at rates of 1.0 lb/ac or more, and 2 applications (2 weeks apart) were more effective than a single application. Thidiazuron was effective only when 2 applications were made. Yields were not reduced by any of the treatments. In a separate field test, ethephon at 1 or 2 lb/ac significantly reduced the populations of boll weevils, Anthonomus grandis Boheman; however, the 2 lb/ac rate also reduced yields by 12%.