June 13, 2013
Q. How do I get rid of wireworms? I have a bad infestation that killed half the grass in my backyard by the end of last year. Now more larvae have hatched.

A. Wireworms are the larvae of a group of beetles commonly called click beetles. The adults are called click beetles because they make a clicking sound as they flip from their backs to their feet. Wireworm larvae are yellow or brown worms that appear segmented and are a half-inch to over 1 inch (1.2-2.5 cm) in length. They can be distinguished from other immature insects by the tough wire-like appearance in contrast to most soft-bodied immature stages of other insects. The larvae have six tiny legs close to the head. Adult wireworms (the beetle), are 0.5-2.0 cm (0.25-0.75 in) long and dull reddish brown to black in colour, depending on the species. There are almost 400 species of wireworms found across Canada and the U.S. While most are harmless to lawns, some species are serious pests.

Life cycle
For an insect, wireworms have a long life. The complete life cycle takes from two to six years. Most of the life cycle is spent as a larvae feeding on roots. The pupae and adult stage require only a few months before eggs are laid near grass plants and the cycle repeats itself. Female beetles lay eggs in May and June.

Wireworms live in the soil and feed on roots, severing them at ground level or burrowing into shoots causing plants to appear stunted, to wilt or die. They thrive in poorly drained, moist compacted soil. Wireworm feeding in a lawn is often mistaken as drought, because of root damage.

Damage Control
First and foremost, it is important to ensure adequate fertility, a balanced soil pH and low soil compaction to encourage a robust lawn that will be tolerate some insect feeding. Make sure you are mowing and watering properly of course. (courtesy of Nutrilawn).

Nematodes work providing the temperature of the soil is warm enough and there is enough moisture. Check your nurseries for availability. Some people say it is best to use the nematodes in late spring and others in the fall. Doing it twice can be beneficial. Wireworms tend to move up and down in the soil, depending on the weather conditions.