The cotton bollworm, Helicoverpa zea, is a traditional pest of cotton in the United States. Before 1996, most control tactics focused on insecticidal control. In 1996, transgenic cotton (Bt cotton) expressing an insecticidal protein was introduced that eliminated much of the need for foliar insecticides targeting this pest. However, in recent years in some areas cotton expressing 2 to 3 insecticidal proteins has begun to experience unexpected injury from bollworms prompting the need for supplemental insecticides to manage this pest. This presentation will describe some of the biology, feeding habits, crop injury, Bt technology, action thresholds and insecticides associated with bollworm management in cotton. You will learn the differences in currently available Bt technologies, strengths and weaknesses, and the reasons they may fail to adequately control bollworms. Additionally, you will learn when to make supplemental insecticide applications and which insecticides are recommended for controlling bollworms in cotton.
