D3118: Comparative efficacy of aerial application and chemigation for controlling western bean cutworm

Effective pest management involves not only selecting the right insecticide but also choosing the most suitable application method. Western bean cutworm (Striacosta albicosta) is a major pest of corn, primarily controlled through aerial and chemigation application (insecticide application via overhead irrigation system). However, there is still limited information regarding the most effective application method. Therefore, this study hypothesized that control efficacy for S. albicosta differs between aerial and chemigation application methods and depends on the insecticide. We compared the effectiveness of these methods for controlling first and third S. albicosta instars. The commercial insecticides chlorantraniliprole (Vantacor), bifenthrin (Brigade), and chlorantraniliprole + bifenthrin (Elevest) were applied at recommended rates to corn leaves. Aerial application was simulated to deliver 18.7 L/ha (2 GPA), while chemigation was applied at 1.26 cm-ha and 3.14 cm-ha (0.2 and 0.5 ac-in). After application, corn leaf discs were infested with 20 of the first or 10 of the third instars of S. albicosta larvae. Mortality was assessed at 8, 16, and 24 hours. Overall, after 24 hours, aerial application resulted in higher mortality than chemigation, except when applying Elevest for the first instar. There was no statistical difference in insecticide efficacy when applied aerially for both S. albicosta instars. However, within the chemigation application, Elevest showed the greatest efficacy in controlling both larval instars. This research highlights the importance of selecting optimal application method and product to improve insecticide efficacy and provide producers with precise information for successful S. albicosta management in corn.