Southwestern corn borer numbers are increasing in our pheromone traps in several counties in the state this week. We usually see this jump around the first week of July, but just like everything else this year, the corn borers are a little late. Areas with the highest numbers seem to be along I-40 in Lee, St Francis and Prairie Counties. Contact you local County Extension agent to find out if trap catches have jumped in your area. Corn borers do not need to be controlled in Bt corn hybrids (YieldGard, Herculex, SmartStax, Viptera, Intrasect). However, any non-Bt corn, particularly any that was planted late, will be very attractive to these moths and should be watched. The treatment threshold for this pest is 25% infestation. It takes about 3-5 days for eggs to hatch and then larva will feed on the leaves of the plant for several days before entering the stem. Once borers enter the stem, control with a foliar insecticide is impossible. Therefore, applications should be applied before larvae enter the stem. Belt, Intrepid, Prevathon and Beseige are several good residual insecticides that give excellent long lasting control. With any of these products the length of residual depends on the rate used. The higher the rate, the longer the residual. A list of rates and recommended insecticides can be found in the corn section of MP144 Insecticide Recommendations for Arkansas.