Formica opaciventris

This is an uncommon and ecologically conservative grassland species (Trager, pers. comm.) that lives in soil mounds or mounds with some thatching. In New Mexico it is found in Sagebrush scrub and meadows up to the edge of forests (Mackay and Mackay 2002).

Identification
Workers can be recognized as the posterior border is concave as seen in full-face view, and the propodeum is somewhat angulate as seen in profile. The pronotum has several spatulate hairs and the mesonotum has a few short, bristly hairs. The dorsum of the gaster has many scattered, short, bristly hairs and has sparse, silver, appressed pubescence. This species would be considered a member of the microgyna group if the posterior border was not concave. (Mackay and Mackay 2002)

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

Nomenclature

 *  opaciventris. Formica exsectoides var. opaciventris Emery, 1893i: 653 (w.m.) U.S.A. Gregg, 1952b: 14 (q.). Subspecies of exsectoides: Wheeler, W.M. 1913f: 484. Raised to species: Creighton, 1950a: 514.

References based on Global Ant Biodiversity Informatics

 * Allred D. M. 1982. Ants of Utah. The Great Basin Naturalist 42: 415-511.
 * Cole A. C., Jr. 1954. Studies of New Mexico ants. XI. The genus Formica with a description of a new species (Hymenoptera: Formicidae). Journal of the Tennessee Academy of Science 29: 163-167.
 * Cover S. P., and R. A. Johnson. 20011. Checklist of Arizona Ants. Downloaded on January 7th at http://www.asu.edu/clas/sirgtools/AZants-2011%20updatev2.pdf
 * Gregg, R.T. 1963. The Ants of Colorado.
 * Johnson R. Personnal Database. Accessed on February 5th 2014 at http://www.asu.edu/clas/sirgtools/resources.htm
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.
 * Michigan State University, The Albert J. Cook Arthropod Research Collection. Accessed on January 7th 2014 at http://www.arc.ent.msu.edu:8080/collection/index.jsp
 * Wheeler, G.C. and J. Wheeler. 1988. A checklist of the ants of Wyoming. Insecta Mundi 2(3&4):230-239