Camponotus acutirostris

This species is rarely collected. It nests under stones, in areas of rocky gravel. Brood was found in nests in March. (Mackay and Mackay 2002)

Identification
The majors of this species are easily recognized as the clypeus is extended into a sharpened angle or beak-like protection (Fig. 348). The head is wide as seen from front. Major workers and females always have 10 or more erect hairs on the cheeks and malar area. The metanotal suture is well depressed, with the mesosoma in profile. The clypeus of the minor worker is similar, but not as elongate. (Mackay and Mackay 2002)

Tanaemyrmex

Distribution
USA: TX, AZ, NM. MEXICO: Chihuahua.

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

Habitat
In New Mexico: Pinyon-juniper forests, oak forests, with grassy areas between trees, pine forests, usually found in more mesic sites in semiarid areas with yucca and cactus, at between 1560 - 2300 meters elevation. (Mackay and Mackay (2002)

Nomenclature

 *  acutirostris. Camponotus acutirostris Wheeler, W.M. 1910d: 317 (s.w.q.m.) U.S.A. Combination in C. (Myrmoturba): Forel, 1914a: 266; in C. (Camponotus): Emery, 1925b: 74; in C. (Tanaemyrmex): Creighton, 1950a: 375. Senior synonym of clarigaster: Creighton, 1950a: 375.
 * clarigaster. Camponotus acutirostris var. clarigaster Wheeler, W.M. 1915b: 420 (s.) U.S.A. Junior synonym of acutirostris: Creighton, 1950a: 375.

Worker
Major Length. 12-13 mm.; head. 3.5 x 3.3 mm.; scape, 3 mm.; hind tibia 3.9 mm.

With the stature of Camponotus vicinus, but with a proportionally smaller head, which has rounded, convex cheek; and posterior corners and broadly excised posterior border. Eyes feebly convex, rather large. Mandibles 6-toothed. Clypeus carinate, produced in front as a pointed angle, which is slightly turned up at the tip. Just behind this tip the carina is interrupted for a short distance by a feeble transverse impression. The anterolateral border of the clypeus is deeply sinuate on each side. Frontal area and groove distinct; frontal carinae feebly lyrate and more approximate than in vicinus and Camponotus vafer. Antennal scapes slender and terete at the base, neither flattened nor dilated, slightly enlarged at their distal ends. Thorax narrower than the head and shaped much as in vicinus, but the epinotum is more like that of vafer, having its basal surface about twice as long as the declivity. Petiole high and rather narrow, with both anterior and posterior surfaces convex, the former more than the latter; border sharp, feebly emarginate in the middle above. Gaster of the usual shape. Legs long; middle and hind tibiae sulcate on their anterior surfaces and rather triangular in cross section.

Head subopaque, densely shagreened; mandibles, cheeks, gula, sides, frontal area and anterior half of front rather smooth, shining. Mandibles finely and densely striate and coarsely punctate. Cheeks with numerous elongate foveolae; clypeus, front and vertex with large. more scattered and rounded foveolae. The punctures on the sides of the head very small and scattered. Thorax subopaque and shagreened like the head; petiole and gaster more finely shagreened, shining.

Hairs yellow, erect, rather short and sparse on the upper surface of the head, thorax and gaster and border of petiole, more numerous on the gula. Marginal hairs of clypeus rather long and prominent. Cheeks with a few short, erect hairs. Femora with a row of long, sparse hairs on their flexor surfaces; tibiae without hairs on their extensor surfaces, but with a row of stiff graduated bristles along the whole length of their flexor surface. Pubescence very short and dilute, discernible only with difficulty except on the scapes.

Head black; mandibles, clypeus and frontal area deep red; antennal scapes black, with yellow or red bases and tips; funiculi brown or yellow. Thorax and legs yellowish brown; pronotum and, to a less extent, the mesonotum sometimes blackish or dark brown; tibiae and tarsi light brown. Gaster brown, with yellow posterior borders to the segments; venter and base or whole of first segment yellow.

Minor Length, 7.5-9 mm.

Head longer than broad, with straight parallel sides, postocular portion prolonged and rounded, but distinctly narrowed at the occiput. Clypeus like that of the worker major, but the point in the middle of the anterior margin is more obtuse and less projecting. Antennae very slender. Thorax through the pronotum about as broad as the head. Epinotum low, with its base twice as long as the declivity into which it passes without a perceptible angle. Petiole thick and rather conical, with blunt, entire lateral and dorsal border.

Sculpture and pilosity much as in the worker major. Cheeks with a few scattered, erect hairs.

Dull yellow; mandibles and cheeks brown; sides and posterior portions of head darker; dorsal surface of gaster, with the exception of the posterior edges of the segments, light brown. Antennal scapes and tarsi brownish.

Queen
Length, 13 mm.

Resembling the worker major in sculpture, pilosity and color. Head narrower, with straighter, more nearly parallel sides. Epinotum with convex, rounded base, nearly as long as the declivity. Petiole broad and thick, compressed antero-posteriorly near the margin, which is sharp. Thorax smooth and shining, epinotum opaque and shagreened; scutellum, metanotum and pronotum, except for a large anteromedian blotch, dark brown or black. Wings long (15 mm.), scarcely tinged with yellow near the costal margin; veins brown, stigma blackish.

Male
Length, 10 mm.

Head very small, longer than broad, occipital border straight, not broader than the anterior border and equal to the surface on each side between the posterior orbit and the corresponding end of the occipital border. This surface is, not convex, but flat. Cheeks subparallel, straight, not concave. Clypeus with broadly rounded border and reflected edge. Mandibles indistinctly bidentate. Thorax through the insertions of the wings nearly twice as broad as the head, narrowed behind, with the epinotuin as long as broad, rounded and sloping in profile, without distinct basal and declivous surfaces. Petiole very low, thick and blunt, as long as high. Gaster, antennae and legs long and slender.

Mandibles and head subopaque, very finely shagreened; clypeus, cheeks and front with a few coarse punctures. Thorax shagreened like the head, subopaque in front; scutellum, epinotum and gaster smooth, shining, more finely and superficially shagreened.

Hairs pale, short, erect and sparse, most abundant on the gaster, absent on the scapes and tibiae, present in a single row on the flexor surfaces of the femora.

Black; mandibles, distal portion of antennal scapes, genitalia and tarsi brown; articulations of thorax, gaster and legs whitish. Wings whitish hyaline, with pale yellow veins and brownish stigma.

Type Material
Described from numerous workers, one. female and one male taken from a single colony living in the ground under a stone at Alamogordo in the foot-hills of the Sacramento Mts. of New Mexico (G. von Krockow), and several workers from Box Canyon in the same territory (A. G. Ruthven).