European Corn Borer

Ostrinia nubilalis

This European moth is found in northern and central parts of the country and is a serious pest of commercial corn growers (though it is now genetically modified to resist this pest). In the garden it may also attack beans, beans, peppers, potatoes and occasionally cabbage, beets, celery, eggplant, okra, onion and tomatoes. The larvae start feeding on the leaves (leaving small shotgun holes) and tassels but as they get older they bore into the stalks (you may notice frass around the hole in the stem). The damage they cause inside the stem interferes with nutrient movement and can weaken it to the point  where it breaks. They also occasionally bore into the ears, but aren’t easily confused with Corn Earworm. There may be up to 3 generations a year.

Control

Encourage predators (wasps, ladybugs, birds). Don’t leave dead corn plants standing in the ground over the winter as larvae may overwinter there. You can spray with BT, pyrethrum or sabadilla.  Some corn cultivars are resistant.

Image: Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org