It may also climb up the plant and tunnel downward into the whorl, creating the ragged holes. Corn plants from 2 to 24 inches tall may be attacked. In conventional corn, damage is usually confined to weedy border rows along fences, grass waterways and contour strips, while weedy no-till fields may have damage throughout. If they do, ears are usually smaller than normal. Those plants that do not produce ears compete with productive plants for water, nutrients and sunlight.
Small larvae are cream colored with a dark brown or purple band around the body.
Several dark lengthwise stripes may be present. Full grown larvae may lack the dark stripes and band, making them harder to identify. Common stalk borer larvae are usually very active when handled. The common stalk borer is native to North America and is known to attack 176 different plant species. An increase in no-till corn acreage has increased common stalk borer incidence and problems.