Subfamily FORMICINAE
Tribe CAMPONOTINI
Camponotus (Camponotus) americanus Mayr

Ants in the genus Camponotus are collectively known as carpenter ants because some species nest in wood, including man-made structure. This genus includes some of the largest and most common ants in the world, and they are found in all biogeographical regions (Bolton, 1995).  More than 900 species of Camponotus are known worldwide, with 50 species reported from the United States (Hanson and Klotz, 2005), and 20 species found east of the Mississippi River (Deyrup, 2003; Smith, 1979). 

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 americanus 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. 

Camponotus americanus is a large carpenter ant with workers 7-10 mm in length. This species could be easily confused with C. castaneus (Latreille), a similarly colored and sized carpenter ant that invades houses and other buildings with more regularity (although not commonly). Camponotus americanus can be distinguished from C. castaneus by its darker head and erect hairs on the cheeks. In C. castaneus the head is the same color as the rest of the body and the cheeks (especially as seen in the major workers) lack erect hairs. In Mississippi and Alabama (at least) there are spots of darker coloration on the dorsum of the alitrunk on C. americanus, whereas in C. castaneus, the coloration is much more uniform without any mottling or spots of other colors.

This species typically nests in the soil, usually under stones, rotten logs, or sometimes under litter. Because C. americanus is usually a soil nesting species, it is not considered to be a serious economic pest. Alates have been collected from mid March through late May.

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