Dung beetles

Overview

Scarabaeinae is a very large subfamily of scarab beetles known as dung beetles. There are 7,077 currently recognized Scarabaeinae species in 287 genera worldwide.

Scarabaeinae are beneficial insects, not just for their removal and burial of dung. By burying, tunneling, or rolling dung, they transfer it below the soil. This increases micro-organism activity, producing chemical changes in the soil that results in increased plant height and leaf production. Where livestock are raised, they suppress dung flies and nematodes, thereby increasing livestock productivity and saving cattle farmers in North America about 380 million dollars a year.

Most Scarabaeinae feed exclusively on dung. After mating, a pair will tunnel into the soil to create a nest, provision it with balls of dung, and lay eggs in the dung balls.

Description

Worldwide, Scarabaeinae range in size from very small to very large. Adults are 1⁄16″ to 2⅜″ (2 to 60 mm) in length. The largest dung beetle in North America is Carolina dung beetle (Dichotomius carolinus), which is ¾″ to 1 3⁄16″ (20 to 30 mm) in length.

Most Scarabaeinae are dull black.

The antenna club is smooth or sparsely hairy.

The last segment of the abdomen (pygidium) is partly exposed, not covered by the hardened wing covers (elytra). The triangular plate between the wing bases (scutellum) is usually not visible.

The hind legs are placed far back on the abdomen, nearer to the tip of the abdomen than to the middle legs, or about the same distance. On the hind legs, the fourth segment (tibia) has only one spur at the tip.