click beetles

Agriotes is a large genus of click beetles. It is one of the larger genera of the very large family Elateridae. It occurs throughout Europe, western Asia, and North America.

There are 274 currently recognized Agriotes species worldwide, 37 species in North America north of Mexico, and at least 7 species in Minnesota.

Agriotes are found in cultivated fields, in gardens, and in any grassland, including pastures, meadows, parks, lawns, and sports facilities. Adults are found on foliage and flowers. They are active in the spring and early summer. They may occur in large numbers, and they consume foliage, but they are not injurious to plants.

The larvae, called wireworms, live in the soil and consume the roots of plants. They attack a wide variety of agricultural crops, grasses, and other plants. Several Agriotes species are significant agricultural pests in the larval stage. They cause serious economic damage to crops of wheat, barley, oats, corn, tobacco, sugar beets, sugar cane, potatoes, sweet potatoes, strawberries, and most vegetables.

Adults are ⅛″ to ⅜″ (4 to 10 mm) long. The body is long, narrow, oval, strongly flattened, and more or less parallel-sided. The upper parts are brown or black and are evenly covered with fine hairs. The front part of the body is loosely connected to the rear part, and it can be moved independently.

The head is convex in front. The mouthparts are directed downward. The antennae are slender and weakly sawtoothed. They have 11 segments. The second segment is as long, or nearly as long, as the fourth segment.

The plate covering the first segment of the thorax (pronotum) has sharp, backward pointing, rear angles.

The wing covers (elytra) are grooved.

The last part of each leg (tarsus), corresponding to the foot, has 5 segments. The last segment has 2 claws at the tip. The claws are smooth and do not have a tuft of hair at the base.

Sources

24, 27, 29, 30, 82, 83.

This genus has no common name. The common name of the Family Elateridae is click beetles, and it is used here for convenience.

Agriotes sp. click beetles

Agriotes sp., click beetle, photographed on Barnes Prairie, Racine Co., WI on May 29, 2022. When threatened, these beetles load a peg latch, rapidly flex and accelerate up from the ground. They're on their back when they do this. This produces a clicking sound.

Location: Barnes Prairie, Racine Co., WI

Agriotes sp., click beetle, photographed on Barnes Prairie, Racine Co., WI on May 29, 2022. When threatened, these beetles load a peg latch, rapidly flex and accelerate up from the ground. They're on their back when they do this. This produces a clicking sound.