Formica rufa clivia

This ant constructs thatched domes of pine needles, typical of the F. rufa species group, in loam soils. Nests may also be found under stones or logs banked with thatch. Brood was found in nests in June and August, reproductives can be found in nests in August to September; dealate females were also found in August and September. They are very aggressive and attack when the nest is disturbed. Foragers tend aphids on various plants. (Mackay and Mackay 2002)

Identification
This subspecies can be separated from the typical Formica obscuriventris in that the minors are darker, and at least part of the petiole of the majors is somewhat darkened, as compared to workers of Formica obscuriventris, in which the minors are yellow-brown in color and the petiole of the majors is clear yellow or red. Obviously the differences in color are of little significance, and this subspecies is probably a synonym of Formica obscuriventris. (Mackay and Mackay 2002)

Distribution
United States. Central North America south to New Mexico.

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

Habitat
In New Mexico (Mackay and Mackay 2002) - Meadows up to oak woodlands, ponderosa pine-riparian and spruce aspen forests.

Biology
Nest site selected in areas of moderate to sparse cover. Nest begun under log or stone with many of the passages running into the soil. Moderate use made of thatching, often little of this visible on the outside of the nest. Large domes or heaps of thatching rarely produced (Creighton, 1940).

Nomenclature

 *  clivia. Formica rufa subsp. clivia Creighton, 1940a: 8, fig. 1 (w.q.m.) U.S.A. Currently subspecies of obscuriventris: Creighton, 1950a: 494.