These are not corn pests

Now that corn is sprouting, many farmers will walk their fields to make stand counts and to scout for black cutworms. Each year someone sends me insects found in a corn field and asks about potential damage. Correct identification of an insect is the first step in determining if there is a potential problem. Two early-season insects that are often mistaken for pests are crane fly larvae and ground beetle larvae.

Crane fly larvae do not injure corn seeds or seedlings. They feed on decaying organic matter in the soil. They can be considered beneficial insects. They are often thought to be cutworms, but they do not have legs. They do have four, soft horns on their tail end and are light gray or brown without stripes. See the April 22 ICM newsletter, page 45 for illustrations of cutworms.

Ground beetle larvae are often confused with wireworms because they are about the same size and shape. They may be completely black or light-colored with dark, square-shaped spots on their backs. They can be identified by their two large jaws and two soft, slender projections on the tail. These insects can reach a length of 114 inch. Ground beetle larva are beneficial and feed on other insects including cutworms. See the April 15 ICM newsletter, page 35 for illustrations of wireworms.

Updated 05/05/1994 - 1:00pm