HPIPM:Corn Leaf Aphid Sorghum

Authors: John B. Campbell & Frank B. Peairs[1]

Identification (and life cycle/seasonal history)

Corn leaf aphids, Rhopalosiphum maidis (Fitch), are small, 1.5 to 2.5 millimeters (1/16 to 3/32 inch), bluish-green insects with a purplish patch around the base of the cornicles. They are usually wingless with short antennae and prominent cornicles. The head, feet, legs and cornicles of the corn leaf aphid are black. The aphids feed in groups, first appearing in the whorl. Later, as they increase in abundance, they may completely cover tassels and upper leaves. Adult females give birth to live young, they do not lay eggs.

Plant Response and Damage

Corn leaf aphids suck plant juices but damage is usually minor. They develop inside the plant whorl and usually disappear when the sorghum head emerges.

Management Approaches

Biological Control

Many predators and parasites attack corn leaf aphids, such as lady bird beetles and several small parasitic wasps. Many predators attack the aphids and consume them. Parasitic wasps may sting the aphids and lay eggs inside its body. These eggs later hatch and the parasitic larvae consume the aphid from the inside. These beneficial insects often keep corn leaf aphid populations below economic levels. The presence of corn leaf aphids early in the season can allow natural enemies to build up, which, in turn, will then help control greenbugs later in the season.

Chemical Control

Economic sorghum yield losses have not been recorded for the corn leaf aphid. Chemical control generally is not considered necessary.

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.