Common names: There are many species of wireworm with similar life cycles. Common names include wireworm, click beetle and elaterid beetle.
Latin names:  Many species from the family Elateridae (prominent genera include Aeolus, Conoderus, Melanotus, Agriotes and Dalopius) and Tenebrionidae (Eleodes species). A particularly important species is Agriotes lineatus (Agriotes segetis, Elater segetis).

Life cycle and description

• Adult stage: Adult beetles are brownish to black with a hard, elongated, somewhat flat shell, and are 5 to 20mm in length. Adults are active fliers and females burrow into the soil to oviposit. Adults are carnivorous, but are also known to attack the cereal foliage. Adult lifespan can last 10 to 12 months. Adults make an audible clicking noise when flipping over after they have been turned upside down. As a result they are often known as ‘click beetles’.
• Egg stage: Eggs are tiny, round, and pearly white. Several hundred eggs can be deposited by adult females in moist soil in grassy areas. Eggs are laid singly and widely scattered amongst the soil particles. This stage can last from a few days to a few weeks.
• Larval stage: Larvae are known as wireworms. Initially wireworms are white, soft and 10mm long. Mature larvae are about 40mm long, shiny, smooth, sluggish, deep yellow or brownish, and hard but flexible. Larvae have three pairs of short, underdeveloped legs, and obvious segmentation. Larval development can take several months to several years depending on the species.
• Pupal stage: Pupae are white, soft and located in weak cells in the soil.
• Some species have life cycles that last several years and all life cycle stages can be observed in the soil simultaneously.
• Diapause of larvae or adult beetles in the ground occurs during cold periods.
• Larvae migrate vertically and horizontally in the soil according to soil moisture. They are sensitive to heat.

Confirmation

Inspection of soil around damaged seedlings will reveal wireworms. In dry weather, the larvae may be quite deep in the soil.

The adult is often referred to as a ‘click beetle’ as it will make clicking sounds when turned on its back and will continue to flick over until properly upright.

It can be difficult to distinguish between the larvae of wireworms and false wireworms. The last abdominal segment on the false wireworm is short and bluntly pointed compared to that of the wireworm, which is long and sculptured.

Problems with similar symptoms

There are a number of species that cause seedlings to wilt, tiller and lodge, including stem borers and seedcorn maggots.

Why and where it occurs

This pest can survive in practically all soil types but prefers weedy fields. Serious infestation of wireworm is more common when maize follows pasture.

Host range

Extremely varied. Pastures, hay and horticultural crops. Specifically rice, wheat, maize, potatoes, tobacco, carrots, onions, sweet potatoes, cotton, lettuce, melons, peas, beans, cowpeas, sugar beets, firs, garlic, rape, cabbage, turnip rape, sunflower, Jerusalem artichoke, barley, hop, lettuce, flax, lupins, tomato, spruces, peach, rye, clovers and grapevine.

Geograhic distribution

Occurs in all maize-growing areas of the world.

Damage

• Mechanism of damage: Wireworm larvae attack maize seed and bore into roots as plants germinate and grow, resulting in poor crop stand, poor growth, and lodging.
• When damage is important: Heavy infestations are often confined to a small area, such as a single field or a section of a field. However, if infestation is widespread in a field it can result in extensive crop loss through seedling damage and lodging. Losses are greatest if wireworms destroy seeds before they germinate. As some wireworm species have a life cycle that can last several years, damage can continue for more than one season.
• Economic importance: Serious economic damage to maize due to wireworms is rare. However, serious infestations can cause significant yield losses.