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
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
A nest chamber was found under a small downed pitch pine trunk in an open pitch pine forest (southwestern Rhode Island. The chamber contained brood and pupae, and off to one side was a hole leading down into their nest. The soil was sandy. The workers initially were frantic, with some running away and others running into the hole into their nest. After a few minutes a few workers were methodically coming out of the nest, picking up brood, and bringing what they could carry into the nest. (Lubertazzi July 4, 2018, DL04664).
This species is a host for the fungus Ophiocordyceps unilaterialis (Shrestha et al., 2017).
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- 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.
- Creighton, W. S. 1950a. The ants of North America. Bull. Mus. Comp. Zool. 104: 1-585 (page 365, Revived status as species, and senior synonym of rufinasis)
- Eisner, T.; Wilson, E. O. 1952. The morphology of the proventriculus of a formicine ant. Psyche (Camb.) 59: 47-60 PDF
- Emery, C. 1893k. Beiträge zur Kenntniss der nordamerikanischen Ameisenfauna. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 7: 633-682 (page 674, male described, Revived from synonymy as subspecies of castaneus)
- Emery, C. 1925d. Hymenoptera. Fam. Formicidae. Subfam. Formicinae. Genera Insectorum 183: 1-302 (page 74, Combination in C. (Camponotus))
- Mayr, G. 1862. Myrmecologische Studien. Verh. K-K. Zool.-Bot. Ges. Wien 12: 649-776 (page 661, worker, queen described)
- Mayr, G. 1886d. Die Formiciden der Vereinigten Staaten von Nordamerika. Verh. K-K. Zool.-Bot. Ges. Wien 36: 419-464 (page 420, Junior synonym of castaneus)
- Shrestha B, Tanaka E, Hyun MW, Han JG, Kim CS, Jo JW, Han SK, Oh J, Sung JM, Sung GH. 2017. Mycosphere Essay 19. Cordyceps species parasitizing hymenopteran and hemipteran insects. Mycosphere 8(9): 1424–1442 (DOI 10.5943/mycosphere/8/9/8).
- Wheeler, G. C.; Wheeler, J. 1968a. The ant larvae of the subfamily Formicinae (Hymenoptera: Formicidae): supplement. Ann. Entomol. Soc. Am. 61: 205-222 (page 216, larva described)
- Wheeler, W. M. 1910g. The North American ants of the genus Camponotus Mayr. Ann. N. Y. Acad. Sci. 20: 295-354 (page 317, soldier, worker, queen, male described)
- Wheeler, W. M. 1913d. Ants collected in Georgia by Dr. J. C. Bradley and Mr. W. T. Davis. Psyche (Camb.) 20: 112-117 (page 117, Revived from synonymy as subspecies of castaneus)
- Wheeler, W. M. 1917k. A list of Indiana ants. Proc. Indiana Acad. Sci. 26: 460-466 (page 465, Revived from synonymy as subspecies of castaneus)
- Wheeler, W. M. 1932a. A list of the ants of Florida with descriptions of new forms. J. N. Y. Entomol. Soc. 40: 1-17 (page 13, Revived from synonymy as subspecies of castaneus)