One of the most potentially damaging problems facing sweet corn producers is controlling insects that feed on the ear. During the summer months, if you grow sweet corn, you need to watch for corn earworm.
Earworms are moderately hairy larvae that vary in color from yellow to green to red to brownish-black, but they all have a brown head without markings and numerous microscopic spines covering their body. You may find them feeding in the ear tips following silking. The larvae are cannibalistic, rarely is there more than one per ear or whorl.