Wireworms are the larvae of insects commonly known as click beetles. The larvae are long, smooth, very hard-bodied, and yellowish to reddish brown. White grubs are the larvae of scarab beetles such as June beetles (May beetles). They are thick, white, soft-bodied larvae, which curl into a C-shape when disturbed. Either insect may occasionally be a problem when corn follows sod, pasture, or grassy hay. The larvae feed on the roots of grasses and germinating crop seeds and at the base of young plants. Symptoms are missing, wilted, or stunted seedlings and young plants. Check the soil around damaged plants for the larvae.
If losses due to wireworms are severe, about the only thing that can be done is to disk up the affected portion of the field, treat with a soil insecticide (see Chemical Control of Corn Insects table), and replant.
- IPM for Insect Pests of Field Corn - a free Moodle course from the NYS IPM Program