Stigmatomma pallipes

Recognition
The genus Amblyopone with 69 species world wide occurs in tropical and subtropical leaf litter, preying on arthropods. There are three species of Amblyopone in North America. One species A. trigonognatha occurs in North Carolina. A. oregonensis is found in British Colombia, Washington, Oregon, northern California and extends eastward into mesic areas of the Pacific Northwest. Ambylopone pallipes found in the Eastern United States is not a common ant, but it can be discovered by turning over stones and searching carefully through rotten wood on the ground. These small, dark reddish-brown ants are about ¼ inch in length. The eyes are very small, with only one or two facets. There is a row of small teeth on the anterior margin of the clypeus and the mandibles are long and linear with a row of bi-dentate teeth on the inner margin. The petiole is broadly joined to the gaster.

Nesting Habits
The small colonies are most common in wooded areas where they are found in rotten logs and under stones. They prefer moist, cool habitats. Centipedes and beetle larvae appear to be the main food source. In New England these ants are often found nesting under rock walls.

Biology
Colony size is small, often less than 20 to 50 workers. The workers are slow moving, and forage under ground and in rotten logs where they are difficult to find. The pupae are covered with a brown silk case that helps in identification in the field. The queen is worker-like and inconspicuous. The males and females mate during the late summer months.

Ecological and Economic Importance
Predators of centipedes and beetle larvae in forest litter.

Remarks
The highly modified mandibles appear to be specialized for hunting centipedes.

Distribution
This primarily eastern species is widely distributed, occurring in most eastern states except in Maine and Pennsylvania where it has not yet been reported. This species distribution expands westward all the way to California and is found sporadically in the mountains of Arizona.

Etymology
"Pale-footed” Primitive Ant