The first sign of injury appears as broken tassels caused by the borers feeding in the tassel stems. Late in the season its presence is indicated by small round holes at any location on the stalk.
The tunneling within the stalks weakens them so that plants break and fall over. As a result many ears are lost due to spoilage or to being missed by the picker. Feeding on the shank of the ear causes it to fall to the ground.
There are probably three generations a year in South Carolina. Full-grown larvae spend the winter in the stems where they have been feeding, especially down close to the ground.
