One farmer we rode the combine with recently knows what he will do differently next year. He grows non-GMO corn and he noticed several dropped ears at harvest. When he looked closer most of them showed signs of tunneling, meaning corn borer larvae tunneled into the ear shank, weakening it and causing the ear to fall.
He will be scouting for corn borer in his non-GMO fields next year. It won't cause him to give up non-GMO corn because he gets a premium, but he will scout to see if it needs treatment. Since scouting and treating corn borer can be tricky, he will refer to Extension information and work with his chemical supplier to try to make the right decision in each field.
He also knows that corn borers might not be a problem next year. It's a pest that is worse some years than others, depending upon weather conditions. Weather in the spring when moths are flying has a lot to do with whether corn borers take hold in non-GMO corn or not.
Dave Nanda, Director of Genetics and Technology for Seed Consultants, Inc., certainly isn't against treating corn borers during the season if the damage warrants it and the application can be made in a timely manner. However, he notes that on the flip side, seeing some corn borer activity isn't all bad. It means the population is surviving, and it's important for it to survive to maintain the integrity of the Bt events that kill corn borer larvae, often with one nibble, in Bt corn borer- protected corn.
It's also important to maintain refuge, and that is often easier now that refuge -in-a-bag products that include a non-GMO hybrid at a small percentage mixed in with the Bt hybrid. The percentage of the mix depends upon the product. Be sure you understand the refuge concept and what you need to do to comply for all Bt traits that you use.