There are several different species of click beetles in Canada, six of which are destructive crop pests. The beetles get their name from the clicking sounds they make. When grabbed or flipped upside down, click beetles snap the top and bottom halves of their bodies to launch themselves into the air, making the clicking sound. While this helps them escape predators, it can also startle residents when the pests move into homes, gardens, and yards.
Appearance / Identification
Click beetle larva picture to aid in identification
Adult click beetles are black, brown, or grey and about 12 to 40 mm long. Some species have dark, round marks on their backs to mimic the eyes of larger animals. Their larvae get the name wireworms from their slender, segmented, and shiny appearance. Despite looking like worms at first glance, the larvae actually have six small legs and tough tan, white, or brown bodies. They can be told apart from other grubs that infest plants by their forward-facing mouthparts.
Adults are typically found under stones, in decaying wood, hiding under bark, or on plants. Most click beetle larvae live and develop in soil near areas with plenty of vegetation, especially farmland and gardens.
The diet of adult and larval click beetles varies greatly. Some species of wireworms eat other ground pests, but most feed on the seeds and roots of crops such as potatoes, beans, cotton, corn, wheat, carrots, beets, melons, onions, and strawberries. Turf grasses and ornamental plants can also be food sources. In contrast, adult beetles do not damage plants, but feed on nectar, pollen, flowers, and soft-bodied pest insects like aphids.
Life Cycle / Reproduction
Female adult click beetles lay their eggs in cultivated fields among weeds or cereal crops. In a week or less, larvae emerge and begin to eat surrounding plant matter. Wireworms may remain larvae for one to six years before changing into adults, depending on their species.
Problems Caused by Click Beetles
Click beetles are often considered pests because of the damage larvae do to crops. In yards and gardens, the pests may harm fruits, vegetables, decorative plant bulbs, or lawn turf by drilling into tubers or eating away roots.
Adult click beetles are occasional pests indoors. They enter the indoors searching for prey or to escape the outside elements. Homes located near an infested field or garden are the most likely to see the pests inside. They don’t breed in houses or bite, but their loud clicking and sudden flips can be a nuisance.
Detection / Signs of Infestation
Residents are most likely to see click beetles at night around doorways and windows. Since they are attracted to light, rooms that keep nightlights on after dark are also good places to spot them. To identify click beetles, listen for snapping sounds and watch for jumping or flipping.
Click beetles are less likely to enter yards with reduced outdoor lighting. Turning off indoor lights may also keep the pests from gathering on the sides of buildings at night. To keep them from entering homes, repair holes in door and window screens and make sure that windows, doors, eaves, and chimneys seal tightly.
Control / Removal
In addition to non-chemical controls, pesticides can be used as a solution to click beetle problems in houses, gardens, fields, and lawns. Always choose and use a product that is registered and labelled for that purpose. Read and follow label directions carefully. It is always best to call a pest control specialist for the safest solution to click beetle problems.