Camponotus americanus

Identification
Highly variable in color, including between individuals of the same colony. The only features in which it seems always to differ from the typical Camponotus castaneus are the deeper and more elongate foveolae on the cheeks of the major workers and the coloration of the head, which is black or dark brown in all four phases, with the mandibles, clypeus and cheeks more or less brown or reddish. The thorax, gaster, legs and antennae of the worker major may be dirty or clay-yellow throughout, but usually the dorsal surface of the thorax, especially of the mesonotum, and a broad transverse band on each gastric segment are light or dark brown. Some specimens have the thorax and gaster piceous, with the thoracic dorsum and gastric bands black; or more rarely the body may be black, with the pronotum, legs and petiole dark red or brown. In the female, the thorax is nearly always black above, the gaster dark brown or with yellow base and pale borders to the segments. The male usually has the thorax, gaster, petiole, legs, antennae and anterior portions of the head brown or piceous, but specimens are occasionally found with the thorax land gaster black. The wings of the female and male are, as a rule, less suffused with yellow than in the typical castaneus. C. americanus occurs over much the same territory as castaneus, but it ranges further north and is much more common. (Wheeler 1910)

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

Nomenclature

 *  americanus. Camponotus americanus Mayr, 1862: 661 (w.q.) U.S.A. Emery, 1893i: 674 (m.); Wheeler, G.C. & Wheeler, J. 1968: 216 (l.). Combination in C. (Camponotus): Emery, 1925b: 74. Junior synonym of castaneus: Mayr, 1886d: 420. Revived from synonymy as subspecies of castaneus: Emery, 1893i: 674; Wheeler, W.M. 1913c: 117; Wheeler, W.M. 1917i: 465; Wheeler, W.M. 1932a: 13. Revived status as species and senior synonym of rufinasis: Creighton, 1950a: 365. See also: Eisner & Wilson, 1952: 47.
 * rufinasis. Camponotus (Camponotus) castaneus st. rufinasis Santschi, 1936b: 204 (s.w.) U.S.A. Raised to species: Santschi, 1937h: 380. Junior synonym of americanus: Creighton, 1950a: 365.