Formica microgyna

Nests are found under stones and logs, occasionally with thatching. Reproductives were found in nests in August. This species enslaves Formica argentea, Formica fusca, Formica lasioides and Formica neogagates. (Mackay and Mackay 2002)

Identification
Robust, large bodied workers, bicolored (head and mesosoma red, gaster black), with numerous blunt, erect hairs on various body parts, especially the pronotum. The tibiae have erect hairs on all surfaces, including a double row on the flexor surfaces. The gaster is dull, except for a band at the end of each tergum, the surface is dull and covered with dense, appressed pubescence. The erect hairs are white, silver or pale yellow in color, and are abundant, especially on the pronotum, mesonotum, propodeum and gaster. Those on the gaster vary in length. Most of the hairs on the mesosoma are blunt tipped, or even weakly spatulate. (Mackay and Mackay 2002)

The queen is a tiny specimen, about two-thirds the size of the largest worker. The scape and tibiae have numerous suberect and erect hairs, as do all surfaces of the head, the dorsum of mesosoma, the petiole, and the dorsum of the gaster. The hairs are longer than those of the major worker, with sharper tips.

The numerous erect hairs on the tibiae would separate this species from most of the others, except for Formica impexa. It can be separated from the latter species, as the propodeum is higher and the erect hairs on the gaster are of several different lengths. It is possible that F. impexa will be shown to be a synonym when more material becomes available.

Distribution
Canada, Alberta. United States. Wyoming south to New Mexico, west to Utah.

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

Habitat
In New Mexico (Mackay and Mackay 2002) - Meadows and open forests, pine and aspen forests.

Biology
In Colorado, Gregg (1963) found this species in coniferous forests, mixed forests, and foothill meadows; nests were under stones or wood, in rotten wood or in thatch.

Hosts for Formica microgyna (Mackay & Mackay, 2002):

Nevada, Wheeler and Wheeler (1986) - We have 6 records from 5 localities. One was in Sarcobatus Subclimax in the Cool Desert and one was in the Alpine Biome. Both of these were nesting under half-buried stones.

Nomenclature

 *  microgyna. Formica microgyna Wheeler, W.M. 1903e: 645, fig. 3 (w.q.m.) U.S.A. Senior synonym of recidiva: Creighton, 1950a: 504. See also: Wheeler, W.M. 1903f: 656; Wheeler, W.M. 1913f: 465; Letendre & Huot, 1972: 117.
 * recidiva. Formica microgyna var. recidiva Wheeler, W.M. 1913f: 395 (in key) (w.) U.S.A. [Formica microgyna subsp. microgyna var. recidiva Wheeler, W.M. 1913f: 467 (w.m.); unavailable name.] Subspecies of microgyna: Wheeler, W.M. 1917a: 542. Junior synonym of microgyna: Creighton, 1950a: 504.

References based on Global Ant Biodiversity Informatics

 * Allred D. M. 1982. Ants of Utah. The Great Basin Naturalist 42: 415-511.
 * Allred D. M., and A. C. Cole, Jr. 1971. Ants of the National Reactor Testing Station. Great Basin Naturalist 31: 237-242.
 * Allred, D.M. 1982. The ants of Utah. Great Basin Naturalist 42:415-511.
 * Borchert, H.F. and N.L. Anderson. 1973. The Ants of the Bearpaw Mountains of Montana (Hymenoptera: Formicidae). Journal of the Kansas Entomological Society 46(2):200-224
 * Glasier J. R. N., S. Nielsen, J. H. Acorn, L. H. Borysenko, and T. Radtke. 2016. A checklist of ants (Hymenoptera: Formicidae) of Saskatchewan. The Canadian Field-Naturalist 130(1): 40-48.
 * Gregg, R.T. 1963. The Ants of Colorado.
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.
 * Mackay, W., D. Lowrie, A. Fisher, E. Mackay, F. Barnes and D. Lowrie. 1988. The ants of Los Alamos County, New Mexico (Hymenoptera: Formicidae). pages 79-131 in J.C. Trager, editor, Advances in Myrmecololgy.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wheeler G. C., and J. Wheeler. 1986. The ants of Nevada. Los Angeles: Natural History Museum of Los Angeles County, vii + 138 pp.
 * Wheeler W. M. 1903. Extraordinary females in three species of Formica, with remarks on mutation in the Formicidae. Bulletin of the American Museum of Natural History. 19: 639-651.
 * Wheeler, G.C. and J. Wheeler. 1988. A checklist of the ants of Montana. Psyche 95:101-114
 * Wheeler, G.C. and J. Wheeler. 1988. A checklist of the ants of Wyoming. Insecta Mundi 2(3&4):230-239