Formica propinqua

This species nests next to logs and stumps, in thatched nests.

Identification
Workers can be recognized by the distribution of erect hairs. The posterior lateral corners and scapes have none (except at apex of scape), the dorsal and ventral surfaces of the head have several (at least 12 on ventral surface of head), the dorsum of the mesosoma has several short, fine erect hairs (most < 0.1 mm in length), the petiole has several similar hairs, and the dorsum of the gaster has several erect hairs which are slightly longer and slightly coarser than those on the pronotum. Most surfaces, including the clypeus, underside of the head and the gena, are dull or only weakly shining. The mid and hind tibiae have a few erect bristles (about 5 on each of the 2 parallel rows), but they extend the entire length of the tibiae. (Mackay and Mackay 2002)

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

Habitat
In New Mexico (Mackay and Mackay 2002) - Forests.

Biology
Nevada, Wheeler and Wheeler (1986) - Our 21 records are mostly concentrated near Lake Tahoe, but 5 are widely scattered elsewhere. The records represent 19 localities 3,900-7,800 ft. Three records were in the Cool Desert (I in a disturbed area), 2 in Pinyon-Juniper Biome, and 9 in the Coniferous Forest Biome. The nest (Figs. 49, 50) of this species was typically a messy pile of thatch on, in, under or against a dead stump or prostrate trunk, the latter on or several feet above the ground. Polycaly was common. The workers were numerous, active, and aggressive. Their bite was annoying and they were quick to becloud the atmosphere with formic acid. We found Myrmecophila (probably oregonensis) (Orthoptera: Gryllidae; det. A.B. Gurney) in a nest at Hobart Creek Reservoir (Washoe Co.), 7,200 ft.

Nest site selected in areas of moderate to heavy cover. Nest begun in or under a log or stump. Extensive use made of thatching. The finished nest considerably influenced by the size of the object in which it was started but, when this is small, a dome shaped nest results (Creighton, 1940)

Nomenclature

 *  propinqua. Formica rufa subsp. propinqua Creighton, 1940a: 1, fig. 1 (w.) U.S.A. [First available use of Formica truncicola subsp. integroides var. propinqua Wheeler, W.M. 1917a: 538; unavailable name.] Cole, 1956f: 257 (q.m.). Subspecies of integroides: Creighton, 1950a: 490. Raised to species: Wheeler, G.C. & Wheeler, J. 1986g: 85; Mackay, Lowrie, et al. 1988: 112 (in key).