By Glenn Studebaker, Extension Entomologist/IPM Coordinator
Southwestern corn borer pheromone trap catches have jumped up this week in Woodruff county. Several traps hit above 200 moths per trap per week. We generally recommend treating conventional corn when numbers hit 100 or more per trap this time of year. This only applies to non-Bt corn hybrids. Bt corn hybrids are protected from southwestern corn borer and do not require a foliar insecticide. Applying an insecticide with a long residual is recommended. Insecticides and recommended rates are listed in the table below.Recommended insecticides can also be found in MP144 Insecticide Recommendations for Arkansas (https://www.uaex.edu/publications/mp-144.aspxor at https://mp144.uaex.edu/default.aspxfor the mobile friendly version). It is important that an application be applied before larva enter the stalk. Eggs hatch in 3-5 days and larva feed for another 3-4 days before entering the stalk.
“This work is supported by the Crop Protection and Pest Management Program [grant no. 2017-70006-27279/project accession no. 1013890] from the USDA National Institute of Food and Agriculture.”