Subfamily FORMICINAE Author: Joe A. MacGown |
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 Camponotus pennsylvanicus, full face view of major worker (MS, Covington Co.) (Photo by Joe A. MacGown). |
 Camponotus pennsylvanicus, lateral view of major worker (MS, Covington Co.) (Photo by Joe A. MacGown) |
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 Camponotus pennsylvanicus, full face view of minor worker (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
 Camponotus pennsylvanicus, lateral view of minor worker (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
 Camponotus pennsylvanicus, dorsal view of minor worker (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
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 Camponotus pennsylvanicus, dorsal view of an alate queen (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
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 Camponotus pennsylvanicus, full face view of a male. (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
 Camponotus pennsylvanicus, lateral view of a male (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
 Camponotus pennsylvanicus, dorsal view of a male (MS, DeSoto Co.) (Photo by Joe A. MacGown). |
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Introduction
Camponotus Mayr, 1861 is a large and widespread genus of polymorphic ants (Bolton 1995). More than 900 species are recognized globally, with approximately 50 reported from the United States (Hansen and Klotz 2005), and about 20 occurring east of the Mississippi River (Deyrup 2003, Smith 1979).
Ants in the genus Camponotus are collectively known as carpenter ants because some species nest in wood, including man-made structures. This genus includes some of the largest and most common ants in the world, and they are found in all biogeographical regions (Bolton 1995).
Species in this genus are variable in size with workers ranging in size from 3 to 15 mm or more in length and queens (also referred to as females) of some species attaining a length of 19 mm or more. Many species are polymorphic. Workers have a 12-segmented antenna that lacks an apical club. Antennal fossae do not touch the posterior border of the clypeus. Ocelli are not present on the heads of workers. The workers of most species have an indistinct metanotal suture between the promesonotum and the propodeum, although this suture is present in C. sexguttatus and some members of the subgenus Colobopsis. Those species that lack the obvoius and deep metanotal suture have the shape of the alitrunk in a smoothly curved arc (as seen in profile).
Camponotus pennsylvanicus is in the subgenus Camponotus, which includes some of the true carpenter ants that nest in wood. Species in this subgenus are large ants with workers ranging approximately 6-14 mm in length. The clypeus is ecarinate to only scarcely carinate, antennal scapes are not flattened at the bases, clypeal fossae are well developed, and the heads of major workers are usually broader than long. This subgenus includes three species in Mississippi.
Common name
Black carpenter ant
Diagnosis
Workers of C. pennsylvanicus is a large, (6-13 mm long). All castes of this species, including the major and minor workers, queens, and males, are black or blackish, although some specimens have dark, reddish-brown coloration on the propodeum, petiole, base of gaster, or bases of legs. This species lacks erect hairs on the gena, malar area, occipital corners of head, and scape, except apically, but has numerous erect hairs on the dorsal surface of the mesosoma, petiole, and the entire surface of the gaster (Fig. 34). Appressed pubescence is sparse on most surfaces of the body but is fairly abundant on the dorsum of the mesosoma, somewhat scattered on the side of the propodeum, and very abundant and long on the gaster. The appressed hairs on the gaster are longer than elsewhere on the body (almost as long as the erect hairs), and most of the hairs overlap bases of hairs positioned more posteriorly.
Some workers of Camponotus pennsylvanicus are similar to dark colored specimens of C. chromaiodes. Camponotus chromaiodes usually has enough reddish color on the posterior portion of the mesosoma to distinguish it from C. pennsylvanicus, but examination of the appressed hairs on the gastral dorsum is sometimes necessary for identification. In C. pennsylvanicus the appressed hairs on the gaster are silvery-white, relatively numerous, and barely overlap the posterior edges of the gastral tergites, with usually much less than a third of the total hair length extending past the edge, whereas in C. chromaiodes, these hairs are golden colored, very numerous, and overlap the posterior margins of the gastral tergites by at least half of their lengths.
Biology and Economic Importance
This is a very common ant that nests in live and dead trees, rotting logs and stumps, and in wood products such as fences, telephone poles, buildings, and sometimes in the soil. Mature nests may have several thousand workers. We have observed individuals of the eastern ant cricket, Myrmecophilus pergandei Bruner, which is associated with a variety of species, in several different colonies of C. pennsylvanicus. Giant bark aphids, Longistigma caryae (Harris), have also been observed in a black carpenter ant colony. Due to their habit of nesting in man-made structures, this species can cause serious damage making it a serious economic pest. Alates have been collected in AL and MS from mid spring through the Fall.
Pest Status
Due to their habit of nesting in man-made structures, this species can cause serious damage making it a serious economic pest.
Distribution
Camponotus pennsylvanicus is a widespread species in eastern and midwestern United States and ranges from New England south to Florida and west to North Dakota and Texas (Smith, 1979).
Literature Cited
Bolton, B. 1995. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp.
Bolton, B. 2025. An online catalog of the ants of the world. Available from https://antcat.org. (accessed 4 November 2025).
Deyrup, M. 2003. An updated list of Florida ants (Hymenoptera: Formicidae). Florida Entomologist 86:43-48.
Hansen, L. D.; Klotz, J. H. 2005. Carpenter ants of the United States and Canada. Ithaca, New York: Cornell University Press, xiii + 204 pp.
Smith, D. R. 1979. Superfamily Formicoidea. Pp. 1323-1467 in: Krombein, K. V.; Hurd, P. D.; Smith, D. R.; Burks, B. D. (eds.) 1979. Catalog of Hymenoptera in America north of Mexico. Volume 2. Apocrita (Aculeata). Washington, D.C.: Smithsonian Institution Press, pp. i-xvi, 1199-2209.
