Prairie mound ant

Prairie mound ant occurs in the United States in the upper Midwest and in the Great Plains states, and in southern Canada from Manitoba to Alberta.

Workers are hairy, uniformly dark brown, and ¼″ to ⅜″ (6 to 9 mm) in length. Queens are 5 ⁄16″ to ½″ (8 to 12 mm) in length.

The head is broadly rounded in outline. The rear margin is rounded, not distinctly concave. The eyes are large. The facial plate above the mouth (clypeus) is not notched. The finger-like sensory mouth part (maxillary palp) is long and has six segments. The basal segment of each antennae (scape) is very long, longer than the length of the head. There are numerous erect hairs on the under (ventral) side of the head, a few hairs on the side of the head extending just to the front edge of the eye, erect hairs at the back of the head at the edge (occipital angle), and usually no erect hairs on the cheek. There are no erect hairs on eyes or on the scape.

The first body segment behind the head (mesosoma) has two distinct elevated areas (bumps). It is covered with three exoskeletal plates, the pronotum and mesonotum covering the thorax, and the propodeum covering the first segment of the abdomen that is fused to the thorax. The pronotum and mesonotum form one smooth convex bump, the propodeum a second convex bump. The second abdominal segment (petiole) is narrow and waist-like, and has a single raised bump (node).

The remainder of the abdomen (gaster) is bulbous. The head, mesosoma, legs, and the gaster are covered with silvery appressed hairs. There are single rows of erect hairs at the end of each segment.

The legs are brown.

Worker: ¼″ to ⅜″ (6 to 9 mm)

Queen: 5 ⁄16″ to ½″ (8 to 12 mm)

Prairies and meadows

Spring to autumn

A single mound may have many queens forming a supercolony.