Corn root aphid

John Van Duyn, North Carolina State University, Entomology Extension Specialist

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Corn root aphids infest the underground portion of corn and many other plants. In the early part of the 20th century it was a serious pest of both corn and cotton. This insect has many hosts and is tended by ants. Ants play a major role in protecting and spreading aphid infestation. Ants may move newly hatched aphids, from overwintered eggs or plant roots, to weed and corn roots. The ants profit from this association by obtaining sugary substance produced by the aphid.

Corn root aphid can be identified by its occurrence on the roots and by the waxy, white substance intermingled with the light bluish-green to near gray aphids. Also, plants supporting aphid colonies will almost always have ants, ant mounds or ant tunnels in the vicinity of the plant.

Symptoms of corn root aphid damage are usually limited to smaller plants and include yellow-purple coloring, stunting, and wilting. The aphids suck juices from the roots and generally compromise the root system. Corn root aphid infestations are common but are seldom of concern. They generally occur in spots with fields. Corn root aphid infestation is most common in fields that are minimally disturbed. Weedy, no-tillage fields are the most likely to support damaging corn root aphid populations.

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This page ( was created by John W. Van Duyn Ph D. Extension Entomologist and Wayne Modlin, and Steven Roberson.

Date Created 1/30/01.
Last revised on 10/31/03.

Published by North Carolina Cooperative Extension Service

Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University at Raleigh, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

CAUTION: The information and recommendations in these Notes were developed for North Carolina conditions and may not apply elsewhere.