Corn leaf aphids infect the swirl of young corn plants. The plants will tolerate large numbers of these aphids. If plants begin to wilt or die, spray them with an insecticide or insecticidal soap. Use as directed on the label.
For more information on this or other topics related to corn production, contact your state extension corn specialist or your local extension educator/agent.
The following is the link to the corn extension specialists: state extension corn specialist