Stenamma huachucanum

Stenamma huachucanum is a cryptic leaf litter ant known mostly from Winkler or Berlese samples of sifted leaf litter. As defined here, the species is widely distributed, occupying both relatively dry, seasonal habitats (e.g. tropical deciduous forest with juniper, oak-pine-juniper woodland, oak woodland, oak-pine-douglas fir forest) and tropical wet forest habitats (e.g. mesophyll forest, cloud forest, oak-pine forest). Collections have been made from 1000–2900 m, but the species is most common between 1600–2500 m. In seasonal habitats, workers have been found underneath rocks, in addition to the leaf litter. (Branstetter, 2013).

Rarely collected. A few collections have come from under stones. One of these was from an area at the edge of a pine-fir woodland and the other from on an open slope. A worker was also found in a leaf litter sample taken from an oak-pine-juniper woodland.

Identification
The species is distinguished by the following characters: Small eye for a Stenamma, the greatest diameter of which is approximately 0.10 mm and has 5-7 ommatidia; very weakly developed dypeal carinae and mesoepinotal impression; pair of extremely smaIl (almost vestigial) tuberculate epinotal spines; the unusually high petiolar node which is much compressed anteroposteriorly; base of gaster almost destitute of longitudinal rugulae, these when present or well developed apparently never exceeding 0.05 mm in length; bicolored appearance, and the delicate sculpturing of the body.

Smith 1957.

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

Range
USA. Arizona. This species is known from the Catalina, Huachuca and Chiricahua Mountains. There is also a record of this species from Colorado (Gregg 1963) and Texas (Van Pelt 1983).

Nomenclature

 *  huachucanum. Stenamma huachucanum Smith, M.R. 1957b: 153, pl. 2, fig. 8 (w.) U.S.A. Branstetter, 2013: 127 (q.).

Type Material
The holotype and eight paratype workers are in the collection of the U. S. National Museum under No. 62393. The remaining paratypes are in the collection of W. S. Creighton.

Type Locality Information
Head of Carr Canyon, Huachuca Mountains, Arizona

Etymology
Toponym. Named for the Huachuca Mountains.

Additional References

 * Branstetter, M.G. 2013. Revision of the Middle American clade of the ant genus Stenamma Westwood (Hymenoptera, Formicidae, Myrmicinae). ZooKeys 295, 1–277.
 * Gregg, R. E. 1963. The ants of Colorado, with reference to their ecology, taxonomy, and geographic distribution. University of Colorado Press, Boulder.
 * Smith, M. R. 1957. Revision of the genus Stenamma Westwood in America north of Mexico (Hymenoptera, Formicidae). American Midland Naturalist. 57:133-174.
 * Van Pelt, A. F. 1983. Ants of the Chisos Mountains, Texas (Hymenoptera: Formicidae). Southwestern Naturalist. 28:137-142.