Stenamma exasperatum

The type specimens were collected under a stone in a "Sequoia grove" (more likely a Sequoiadendron grove). Specimens have also been collected from litter samples and under a stone in a pine-fir forest.

Identification
This species is most closely related to Stenamma heathi with which it shares details of clypeal structure and gastric sculpture. The sculpturation of the head and thorax are similar but in Stenamma exasperatum both are more clearly reticulate. The reticulae become less defined on the sides of the head and thorax of S. heat hi, usually replaced by a series of irregular longitudinal rugulae. Although the hairs of the scapes and tibiae are fully erect in Stenamma exasperatum studied, there may be some variation not now evident. In Stenamma heathi these appendages usually have the hairs strongly decumbent, but in some specimens the hairs may be subdecumbent and with a few which are suberect. The hairs of the hind tibiae apparently are consistently decumbent in Stenamma heathi, fully erect in S. exasperatum.

The erect hairs on the front of the head are conspicuously more abundant in Stenamma exasperatum and are more uniform in length. Some of the hairs on the front of the head of Stenamma heathiare three to four times the length of the shortest hairs and hairs of all lengths are sparser than in S. exasperatum.

Snelling 1973

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Range
USA. Known only from California.

Nomenclature

 *  exasperatum. Stenamma exasperatum Snelling, R.R. 1973c: 28, figs. 40, 41, 46, 47, 63 (w.) U.S.A.

Type Material
Holotype and three paratype workers: all specimens in LACM.

Type Locality Information
Calaveras Big Trees, Calaveras Co., California.

Etymology
Descriptive. Exasperatum, L., so named to express my feeling upon discovering that these specimens, thought to be S. heathi, represent still another species.

Additional References

 * Snelling, R. R. 1973. Studies on California ants. 7. The genus Stenamma (Hymenoptera: Formicidae). Contributions in Science (Los Angeles). 245:1-38.