Stalk borers tunnel into the above-ground portion of the corn plant. Newly emerging leaves from the whorl often have numerous large holes. Injury becomes obvious when the plant terminal begins to wilt and turn brown. Stalk borers are very common pests of corn, especially in rows next to grassy waterways and fence lines. These rows often are stunted in height.
Young larvae have cream-colored stripes along the center of the back and along each side.
A lateral pair of dark brown to purple stripes also extend the length of the body, but they combine to form a purple heart section directly behind the true legs. The dark stripes and purple heart fade in older larvae. All larvae have a dark stripe on each side of the head. Moths lay eggs in grassy or weedy areas during late summer and these hatch the following spring. There is one generation per year.