HPIPM:Western Corn Rootworm

Authors: Gary L. Hein & Frank B. Peairs[1]

The western corn rootworm, Diabrotica virgifera virgifera LeConte is only associated with dry beans when they move from adjoining corn to feed on bean leaves. Control measures are seldom warranted for this insect in dry beans.

Identification (and life cycle/seasonal history)

The western corn rootworm is about ¼ inch in length and has a light yellow to green wing cover with three longitudinal black stripes. They only survive in continuous corn where corn is planted back to corn the following year. Eggs overwinter in the soil and hatch the following summer. Larvae are able to survive only on corn roots.

Plant Response and Damage

The beetles move into beans from adjacent corn and strip the epidermis of leaves, leaving only the lacy appearing cuticle. This damage resembles Mexican bean beetle damage.

Management Approaches

Western corn rootworm beetles can become a problem on dry beans when heavy populations of rootworms develop in adjacent fields of continuous corn, and beetles move to the beans to feed on leaves. Populations of this insect will rarely become significant in beans, and most often are confined to the borders immediately next to the corn.

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.