These shiny, hard-skinned, wire-like larvae are the immatures of click beetles. Wireworms feed on seeds and roots, producing weak plants. Several species of wireworms are involved and, like the white grubs, are more injurious to crops planted on soil that is the first or second year out of sod. The corn wireworm, Melanotus communis, or the wheat wireworm, Agriotes mancus, usually occur in heavier organic soils and tend to disappear with continued cultivation.
Light sandy soils favor the eastern field wireworm, Limonius agonus. Continued cultivation encourages this species. The presence of wireworms in soil may be detected with baits, such as a cut potato, a mixture of untreated wheat and corn seeds, or rolled oats, buried a few inches deep in the soil, marked with a flag, then dug up 2-3 weeks later. If present in large numbers, they may also be visible when the soil is turned over.
Wireworms are difficult to control with available insecticides. Some tactics which may reduce damage are: 1) delay planting for several weeks after plowing so that little food is available, 2) use plastic mulch between rows to heat the soil above the wireworms' preferred temperature.