Formica neorufibarbis

This insignificant-appearing ant is a record-holder. It occupies a territory much greater than that of any other Nearctic species of the fusca group. It also holds the elevational record for the Nearctic ant fauna: 14,269 ft. on Mt. Evans in Colorado (Gregg, 1963). Similarly it holds the altitudinal record in Nevada: 12,160 ft. on Boundary Peak. Formica neorufibarbis is a common, widely distributed species. Nests may be found under stones or logs and in rotten logs and stumps in areas of rocky sand or loam.

Identification
This species has few erect hairs, the gaster is polished and strongly shining, the surface is little hidden by sparse pubescence. The metasternal process is poorly developed, but is usually surrounded by erect hairs. The area between the anterior edge of the eye and the mandible has elongate punctures, which are often difficult to see unless the surface is held obliquely and the light is directed from the side. The shiny gaster usually suggests the neorufibarbis species complex, the other characters, especially the lack of hairs on the ventral surface of the head and dorsum of the petiole, together with the elongate punctures on the gena, confirm the identification. (Mackay and Mackay 2002)

Distribution
An enormous triangle from western Alaska on the Bering Strait and the Mackenzie Delta (on the border of the Arctic Ocean) to an apex on Newfoundland; thence southwestward to New Mexico, Arizona, California and into northern Mexico; its base extends northward along the Pacific Coast to southern and central Alaska.

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



Habitat
In New Mexico (Mackay and Mackay 2002) - Sagebrush, grasslands, pinyon-juniper, up to spruce and aspen, fir, riparian cottonwood forests and ponderosa pine forests.

Biology
"This ant represents a characteristic element of the boreal coniferous forest .... It is the Formica which endures the most severe climate in North America and one of the few ants that can breach the boundary of the tundra .... This ant which is very timid feeds on honeydew and dead arthropods. It seems to gather little from flowers" (translation from Francoeur, 1973).

Bernstein (1976) reported that 85% of the food collected is liquid from plants, mostly flowers. Regardless of abundance of food, all foraging ceases as soon as the brood is mature. The brood is reared quickly, an adaptation to a short summer. The smaller workers are nearly black; therefore they warm up earlier in the day. A larger body tends to heat up more slowly and a redder color probably reflects more solar radiation than would a blacker color. "Color and size differences ... enable each colony to utilize a greater range of environmental conditions for foraging than if they were of a single size and color."

For New Mexico (Mackay and Mackay 2002) - Brood was found in nests in July and August, reproductives were in nests in August. The diurnal foragers are found in chollas (Opuntia sp.). This species is enslaved by other species of Formica (Formica adamsi alpina) and by Polyergus breviceps.

Nevada, Wheeler and Wheeler (1986) - Our 104 records represent 51 localities scattered statewide. The elevational range is 5,000-12,160 ft.; 79% were above 8,000 ft. and 51% were above 10,000 ft. One record was from the Pinyon-Juniper Biome, 22 were in the Coniferous Forest Biome, 9 in the ecotone above it, and 42 from the Alpine Biome. Thirty-three colonies nested under stones; 27 were in and/or under rotten wood lying on the ground or partially buried and 1 was in the root system of a phlox-like plant. The workers were fast and aggressive and the bite was annoying. We found 1 colony enslaved by Formica aserva.

Castes

 * Worker

Nomenclature

 *  neorufibarbis. Formica fusca var. neorufibarbis Emery, 1893i: 660 (w.) U.S.A. Forel, 1902i: 699 (q.); Wheeler, W.M. 1917a: 547 (m.); Wheeler, G.C. & Wheeler, J. 1953c: 165 (l.). Combination in F. (Serviformica): Emery, 1925b: 248. Subspecies of fusca: Wheeler, G.C. & Wheeler, E.W. 1944: 261. Raised to species: Creighton, 1950a: 537. Senior synonym of algida, gelida: Francoeur, 1973: 215.
 * gelida. Formica fusca var. gelida Wheeler, W.M. 1913f: 399 (in key) (w.q.m.) U.S.A. [Formica fusca subsp. fusca var. gelida Wheeler, W.M. 1913f: 505; unavailable name.] Subspecies of fusca: Wheeler, W.M. 1917a: 546; of neorufibarbis: Creighton, 1950a: 537. Junior synonym of neorufibarbis: Francoeur, 1973: 215.
 * algida. Formica fusca var. algida Wheeler, W.M. 1915f: 205 (w.q.) U.S.A. Combination in F. (Serviformica): Emery, 1925b: 248. Subspecies of neorufibarbis: Creighton, 1950a: 537. Junior synonym of neorufibarbis: Francoeur, 1973: 215.