In 1989, continued field evaluation of Heliothis virescens moths with the adult vial technique (AVT) showed moderately increased tolerance to cypermethrin compared to 1988. Early season testing demonstrated the benefits of the pyrethroid management program in reducing the tolerance of the field population prior to late season intensive use of pyrethroids. The value of AVT testing for monitoring field populations, and the use of test results for predicting field performance will be discussed.