Wireworms on Corn

Several species of wireworms are found in corn fields in South Carolina. In the past, tobacco wireworms and sand wireworms have been the only two species of consequence. However, the sand wireworm has been replaced by the southern potato wireworm in importance. The adults, known as "click beetles," are fairly distinguishable from one another. However, the larvae are quite hard to tell apart. Since life history and control practices are essentially the same, they will not be distinguished here.

Wireworm eggs are usually laid in the summer. When the eggs hatch, the larvae feed on a variety of different roots, overwintering in one of several larval instars, or stages. As corn is planted in the spring, wireworm larvae that are present feed on the corn kernels, causing poor germination and stunted, sickly-looking plants.

Damage due to wireworms varies from year to year. There may be serious damage some years, and practically no damage in other years. Some damage, however, occurs nearly every year.

Proper crop rotation may be of only limited value against wireworms. Some fields are problem fields year after year. Rotation away from such fields would be advantageous. On the other hand, rotation into such a field may result in considerable wireworm problems even if corn had never been planted there before.

A banded application of a labeled insecticide at planting or pre-planting gives the best control of wireworms. Since the list of labeled products is constantly changing, and since available products varies from state to state, there will be no mention of specific products. With all insecticides, read and follow label instructions carefully.

Prepared by Donald G. Manley, Extension Entomologist/Professor,  Department of Entomology, Soils, and Plant Sciences, Clemson University.

This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. Brand names of pesticides are given as a convenience and are neither an endorsement nor guarantee of the product nor a suggestion that similar products are not effective. Use pesticides only according to the directions on the label. Follow all directions, precautions and restrictions that are listed.

The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer. Clemson University Cooperating with U.S. Department of Agriculture and South Carolina Counties. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914.