As a result, much attention needs to be focused on early recognition of both pests and their injury so control measures may be employed at the most appropriate time. Key to Pests of Corn and Sorghum A. Insects that feed on seed, roots, lower stems, or surface debris. They may or may not be able to fly. Plants which survive display yellow streaks, suckering, and rows of holes transverse across the blades. As it feeds below the ground line on the lower stalks of corn seedlings, a large ragged hole is left in the stalk.
Damage is most common in corn following sod.
Billbug larvae range from 2 to 15 mm long. The last segment of the body has a brown, dorsal shield. They feed heavily on roots of grass crops, stunting and sometimes killing plants. Taproots of recently infested plants usually display an irregular feeding hole with jelly-like plant secretions. Damage to germinating corn is common.