Since 2010, aphids have been colonizing corn later in the summer and can build up to surprising levels in Iowa. They can be found at the base of the stalk, around the ear and sometimes above the ear leaf. Aphids have been sighted in corn again this summer.
Aphids have been confirmed in corn fields for about two weeks, particularly in north central and northeastern Iowa. In some fields, the infestations are only along the edge rows, but in others, aphids may extend into the field interior. Spot checking fields for aphid activity is recommended as the growing season progresses.