Camponotus hyatti

Camponotus hyatti is a highly polymoprhic species with majors, medias and minors. It is found nesting inside wood, including oaks, manzanita, chemise, sagebrush, and inside the hollow base of thick shrubs including Yucca and Ephedra. This species belongs to the subgenus Myrmentoma, a Holarctic group of small to medium sized carpenter ants. There is a distinct notch in the middle of the anterior margin of the clypeus in this subgenus which has about 13 North American species.

Identification
Camponotus hyatti is a member of a complex of western North American species characterized by sparsely punctate 5-toothed mandibles, and the flattened, shiny sparsely punctate clypeus of the major workers and female reproductives. In the major workers, the entire frontal and malar area of the head is smooth and shiny. There is a distinct metanotal groove. The basal face of the propodeum is convex in profile rather than flat. There are only a few erect hairs on the dorsum of the pronotum and mesonotum.

Mackay and Mackay (2002) - The majors of this species can be recognized by the deep impression at the metanotal suture, and by the convex dorsal face and concave posterior face of the propodeum. They are generally bicolored, with the head and mesosoma reddish-brown, and the gaster dark brown. The antennal scapes fail to reach the posterior lateral corners by about 2 funicular segments. The petiole is slender as seen in profile. The majors have few erect hairs, with none on the sides of the head, on the cheeks, or on the scapes. The dorsal and posterior faces of the propodeum are about equal in length. There are usually few erect hairs on the dorsum of the mesosoma, on the petiole, and dorsum of the gaster. Most surfaces are at least moderately shining, the gaster is transversely striolate and shining. The area between the punctures on the mandibles and the dorsum of the gaster are smooth and shining. The minors are similar, with the metanotal suture impressed on the dorsum of the mesosoma, but not as deeply as in the major worker. The pilosity, sculpture, and color are similar to that of the major workers.

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

Biology
Colonies are found nesting in the hollow base of thick shrubs such as Yucca and Ephedra. Polymorphic workers forage during the day. Nest size can be more than 200 workers. Reproductives fly during the summer rains. Males and reproductive females can be found in nests as late as early August on the Colorado Plateau. There is a single reproductive queen in the nest.

Mackay and Mackay (2002), in New Mexico: Camponotus hyatti appears to be limited to areas of sagebrush at around 1770 m elevation, where it nests in sagebrush roots (Artemesia spp.).

Castes
Polymorphic workers include majors, medias and minors.

Nomenclature

 *  hyatti. Camponotus hyatti Emery, 1893i: 680, pl. 22, figs. 25, 26 (s.w.) U.S.A. Combination in C. (Camponotus): Forel, 1914a: 266; in C. (Myrmentoma): Emery, 1920b: 257. Senior synonym of californica: Snelling, R.R. 1988: 69.
 * bicolor. Camponotus sayi subsp. bicolor Pergande, 1894: 161 (s.w.q.m.) MEXICO. [Junior secondary homonym of Formica bicolor Latreille, 1798, above.] Replacement name: californicus Emery, 1925b: 118.
 * californica. Camponotus (Myrmentoma) sayi subsp. californica Emery, 1925b: 118. Replacement name for Camponotus sayi subsp. bicolor Pergande, 1894: 161. [Junior secondary homonym of Formica bicolor Latreille, 1798: 43.] Junior synonym of sayi: Snelling, R.R. 1968b: 355; of hyatti: Snelling, R.R. 1988: 69.