Author: Dr. Steve L. Brown, Dr. Will Hudson, University of Georgia
The term "wireworm" is used to describe the larval form of several different species of "click beetles". As the name implies, they are slender and hard and feel somewhat like a wire. Their bodies are distinctly segmented and shiny. Some of the most common species are white with the head and last segment reddish-brown. However, wireworms having other colors may be found. There are three pairs of legs directly behind the head and no prolegs.
Wireworms may feed on the underground portions of virtually any plant. The most commonly damaged crops in Georgia are sweet potatoes, peanuts, corn, and tobacco.
Wireworms may attack germinating seed of corn and small grains resulting in skippy stands. Tobacco transplants are often damaged but not killed, resulting in weakened, stunted plants. Peanuts and sweet potatoes that have been attacked by wireworms will have feeding marks that range from small clean holes to larger, irregular holes. Damaged peanut pods will decay in the soil. Damage to sweet potatoes will "heal", but marketability may be greatly reduced by the resulting blemishes.
Depending on the species, wireworm life cycles will vary from several weeks to two years. Larvae and pupae are found in the soil. Adults (click beetles) emerge throughout the summer months and are commonly found in protected places during the day and around lights at night.
Although complete control is virtually impossible, avoiding fields that have a history of wireworm problems will help. Low-lying, sandy fields tend to have the most problems, and click beetles seem to return to the same fields to lay eggs. Soil-applied insecticides can be effective if applied in a timely manner. Preventative applications tend to be more successful than rescue treatments.