Wireworms are the larval stage of click beetles. These bugs live in the soil and they feed on the underground parts of plants. You can differentiate these 1/2- to 1 1/2-inch, yellow to brown larvae from millipedes by the number of legs they have. Wireworms have only three pairs located directly behind the head, while millipedes have many. Currently, there are no commercial insecticides available for the home gardener against wireworms, but there are organic ways to reduce the population of wireworms and eventually get rid of them.
Turn the soil frequently with a rototiller or shovel. Turning the soil exposes wireworms to birds and other predators and destroys many of the wireworms, particularly if you use a rototiller.
Make wireworm traps by spearing a piece of potato with a stick. Bury the potato 2 to 4 inches deep with part of the stick above ground. Space the traps 3 to 10 feet apart. Dig up the traps after a week and destroy them. Repeat the process as long as you find wireworms in the potato traps.
Starve out the wireworms. Don't plant a garden for a year if your potato traps are still infested with wireworms at planting time. Another option is to plant the garden with a cover crop of alfalfa or clover. These crops repel wireworms.
Pour syrup over the top of a post located near the garden. Adult click beetles are attracted to the sugar in syrup and become stuck in it. Scrape off and destroy the click beetles.
New gardens recently converted from grass are often infested with wireworms. Test for wireworms with potato traps before planting a new garden. Wireworms have a preference for corn, potatoes, beets, carrots and sweet potatoes; avoid planting these crops in new gardens recently converted from sod.