roundneck sexton beetle

not listed

NNR - Unranked

not listed

Roundneck sexton beetle is common, moderately-sized, North American burying beetle. It occurs throughout the eastern United States and in southern Canada, and in a few widely separated areas in the west. It is active from late May to October but most active in the hot summer months from June to August. It is usually found in deciduous forests and woodlands, but also in grasslands. Adults feed mostly on the feces of carnivores, including humans, but also on carrion, maggots, and rotting fruit.

Roundneck sexton beetle adult is ⅝″ to ⅞″ (15 to 22 mm) long. The head and mouth parts are projected forward. The antennae are black and are abruptly widened at the tip (clubbed). They have 11 segments but the second segment is very small, making it appear that there are only 10 segments. The expanded portion of the club is mostly bright orange, black just at the base. It is covered with velvety hairs (setae).

The body is somewhat flattened and entirely black. The underside is covered with brown hairs. The hardened plate covering the thorax (pronotum) is nearly round and entirely black with no orange markings. It is sharply flattened at the edges with broad margins at the sides and base. The plate between the wing bases (scutellum) is visible, moderate-sized, and entirely black.

The hardened wing covers (elytra) are truncate, appearing cut off at the tip and exposing 2 or 3 body segments. They are covered with long erect hairs. The lateral margins are folded under and are entirely black. The surface is smooth, not ridged. There are two pairs of orange markings on the elytra. The front pair is long and broadly jagged. The rear pair is smaller and more circular but still jagged. The shape of the elytral markings is a key identifying feature for each species within this genus.

The legs are black. The fourth segment (tibia) on each hind leg is straight, not curved. The end part of each leg (tarsus), corresponding to the foot, has 5 segments.

Total length: ⅝″ to ⅞″ (15 to 22 mm)

Mostly woodlands

Late May to October

After finding a carcass, the male will emit pheromones to attract a female. Together they will bury the carcass to keep it moist and prevent it being taken by a scavenger. Both adults feed the larvae.

Adults are attracted to light.

The female lays eggs close to the buried carcass. After they hatch the first stage (instar) larvae are fed by the adults. The adults overwinter.

Decaying flesh regurgitated by the adults.

Mostly feces of carnivores, including humans, but also carrion, maggots, and rotting fruit.

Sources

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

Common

Location: Fairview Twp.

Location: Karlstad, MN