Formica argentea

Identification
The metasternal process of this species is poorly developed, but is often surrounded by abundant hair (exceptions common). The ventral surface of the head is without erect hairs. This species has a silvery sheen on the gaster, due to the abundance of pubescence, the remainder of the ant is usually brownish or even reddish or yellowish brown, with the gaster slightly darker, but may be concolorous black. Sometimes it is weakly bicolored. (Mackay and Mackay 2002)

Distribution
Most of North America and into Mexcio (Chihuahua).

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

Biology
For New Mexico (Mackay and Mackay 2002): Nests are found under stones or logs, or under bark of pines. Brood was found in nests in July and August, sexuals in August. Multiple dealate females occur in nests (at least 3). Nests may have a small amount of thatching mixed with soil. They are generally relatively docile, and rapidly escape when the nest is disturbed. Flights occur in early July (sexuals are attracted to lights); a dealate female was collected in July. This species nests together with Lasius murphyi, as well as with Solenopsis molesta, Monomorium minimum, Lasius sitiens, Lasius pallitarsis, and Camponotus modoc.

Nevada, Wheeler and Wheeler (1986) - This species is very adaptable and is distributed throughout the state. We have 109 records representing 100 localities. Twenty-three records are from the Cool Desert (l from Sarcobatus Subclimax, 1 from a cottonwood grove, 1 from riparian cottonwood grove, 2 from disturbed cottonwood groves, and 1 from a disturbed habitat), 26 are from the Pinyon-Juniper Biome, 30 from the Coniferous Forest Biome, 7 from the ecotone, and 4 from the Alpine Biome. Formica argentea is definitely a montane ant. While the elevational range is 4,400-11,500 ft., 95% of the records are above 6,000 ft. Most (43) nests were under stones, 5 were under wood lying on the ground, 13 were exposed (5 of these under earthen mounds and 8 with excavated soil in craters around the entrance). In a nest of this species we found Hetaerius tristriatus Horn (Coleoptera: Histeridae; det. J.M. Kingsolver), nr summit Sugarloaf Mt. 3 mi. SSE Montgomery Pass, Mineral Co., 9,000 ft. F. argentea was tending Aphis sp. nr penstemonicola G. &F. (Homoptera: Aphididae; det. M.B. Stoetzel), on squaw currant (Ribes cereum), Lehman Caves Nat. Mon., White Pine Co., 6,800 ft.v

Fungi
This species is a host for the ectoparastic fungus Laboulbenia formicarum (Espadaler & Santamaria, 2012).

Nomenclature

 * argentata. Formica fusca var. argentata Wheeler, W.M. 1902e: 952 (footnote) (w.) U.S.A. [Junior primary homonym of argentata Fabricius, above.] Replacement name: argentea Wheeler, W.M. 1912c: 90.
 *  argentea. Formica fusca var. argentea Wheeler, W.M. 1912c: 90. Replacement name for argentata Wheeler, W.M., above. [Junior primary homonym of argentata Fabricius, 1804: 413.] Wheeler, W.M. 1913f: 502 (q.m.). Combination in F. (Serviformica): Emery, 1925b: 248. Subspecies of fusca: Buren, 1944a: 301. Junior synonym of fusca: Creighton, 1950a: 532. Revived from synonymy, raised to species and senior synonym of blanda: Francoeur, 1973: 141.
 * blanda. Formica fusca var. blanda Wheeler, W.M. 1913f: 398 (in key) (w.) U.S.A. [Unresolved junior primary homonym of blanda Smith, F. 1858b: 43, above.] Subspecies of fusca: Wheeler, W.M. 1917a: 548. Junior synonym of argentea: Francoeur, 1973: 141.