ABSTRACT
In 1992, continued field evaluation of Heliothis virescens and Helicoverpa zea male moths by the adult vial technique (AVT) showed moderately increased tolerance to cypermethrin compared to 1991. Early season testing further demonstrated the benefits of the pyrethroid management program in reducing the tolerance of the field population prior to late season intensive insecticide use. In spite of significant survival of Heliothis virescens moths at the 10 ug/vial dose in mid to late season testing, the occurrence of field failures due to resistance continued to be less than 1-2% of the treated acres. Helicoverpa zea did not show significant survival at half of this rate. Exceptionally high insect populations, poorly timed and/or applied sprays and weather in addition to reduced susceptibility lead to field control problems. Recommendations for future management of these pests in cotton will be presented.
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