Camponotus vicinus

Nest chambers are often under a stone or, less frequently, under downed wood.

Identification
The majors, minors, and females of this species have the area at the base of the scape flattened, which is rarely enlarged into a poorly formed lobe. The frontal carinae are widely separated. The cheek, malar area, and sides of head are nearly always are without erect hairs, but up to 3 for 4 hairs may be present on the cheeks (usually located near the base of mandibles), and an erect hair on the ventral surface of the head may be visible in full face view, appearing as an erect hair on the side of the head. The mesosoma has numerous erect hairs, as does the petiole and the gaster, the hairs on the gaster are positioned along the posterior edge of each tergum, as well as nearly always scattered across the surface. The middle and hind tibiae have 2 rows of erect, coarse hairs that extend nearly the entire length of the tibiae, but there are usually fewer than 10 present, and most are on the distal half. The head and mesosoma have a few appressed hairs. The appressed hairs on the gaster are variable, ranging from a few tiny (0.01 mm) hairs, to coarse, long (up to 0.2 mm) hairs. The head is densely and evenly punctate, the mesosoma is coriaceous, and the gaster ranges from smooth and glossy to dull with coarse transverse striae. The color ranges from yellow brown to black, the most common color includes a black head and gaster with a red mesosoma and legs. (Mackay and Mackay 2002)

Distribution
Southwestern Canada, western United States, south to northwestern Mexico.

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

Habitat
In New Mexico (Mackay and Mackay 2002): Chihuahuan Desert, areas of mesquite, sagebrush, meadows, deciduous forests, oak forests, riparian cottonwood forests, ponderosa pine-riparian, pinyon-juniper, ponderosa pine, Douglas fir, aspen forest, usually at higher elevations in relatively mesic sites (1930 - 2960 meters).

Biology
For New Mexico (Mackay and Mackay 2002) - This is a very common species in New Mexico, which nests under stones and logs (rare) in open areas of fine sand to rocky soils. Brood and reproductives were found in nests from March to October, dealate females were captured from March to mid September. A flight occurred on 19-vii-1986 at 7:00 p.m. Nests are occasionally started by pleometrosis (multiple females start nests together). Much of the foraging occurs at night, although workers are also diurnal; workers tend Homoptera. Workers forage into vegetation, especially cholla (Opuntia sp.), and Yucca sp. Workers are attracted to baits, including liver, especially rotten liver. Monomorium minimum, Myrmica striolagaster, Liometopum apiculatum, Leptothorax crassipilis, and Solenopsis live in nests. One nest inhabited an abandoned nest of Pogonomyrmex occidentalis. Gynes are prey of Formica and Solenopsis.

In the Bitterroot Mountains of Montana these ants can be common in open meadows. A single colony can have nest chambers under numerous rocks.

Nevada, Wheeler and Wheeler (1986) - This is one of the commonest and most widely distributed of all Nevada ants. There are two main color phases: one is pale and in the field cannot be distinguished from Camponotus semitestaceus; it occurs in arid and semiarid habitats. We have 197 records in Nevada from 141 localities; 3,900-9,700 ft. Twenty-eight records are from the Cool Desert (including 1 from a Sarcobatus Subclimax, 1 from a cottonwood grove, and 2 riparian), 74 are from the Pinyon-Juniper Biome, and 37 from the Coniferous Forest. The majority (65) of nests were under stones; 9 were under rotten logs lying on the ground; 12 were exposed with excavated soil around the entrance (which sometimes could be called a crater). Entrances ranged from 5 to 30 mm in diameter. Xenodusa angusta Fall (Coleoptera: Staphylinidae; det. RR Snelling) was a guest in a nest. C. vicinus workers were tending waxy scales, Orthezia nigrocincta Cockerell (Homoptera: Ortheziidae; det. D.R Miller), on the roots of Sarcobatus vermiculatus.

Castes

 * Worker

Nomenclature

 *  vicinus. Camponotus vicinus Mayr, 1870b: 940 (w.) U.S.A. Emery, 1893i: 671 (s.q.); Wheeler, W.M. 1910d: 301 (m.); Wheeler, G.C. & Wheeler, J. 1968: 220 (l.). Combination in C. (Myrmoturba): Forel, 1914a: 268; in C. (Camponotus): Emery, 1925b: 75; in C. (Tanaemyrmex): Creighton, 1950a: 381. Subspecies of sylvaticus: Mayr, 1886d: 422; of maculatus: Emery, 1893i: 671; of sansabeanus: Emery, 1920b: 232 (footnote); Cole, 1942: 387. Revived status as species: Creighton, 1950a: 381; Snelling, R.R. 1970: 396. Material of the unavailable names infernalis, luteangulus, maritimus, nitidiventris, plorabilis, subrostrata referred here by Creighton, 1950a: 381; material of the unavailable name berkeleyensis referred here by Snelling, R.R. 1970: 396.