Formica pergandei

Formica pergandei is found in woods, woodland edges, semi-open or open areas near woodland edges, and prairies (Coovert 2005, Nemec et al. 2012). It nests under rotten logs or large branches or in soil. It is a slave-maker and starts its colonies in the nests of host species, including members of the F. fusca, F. pallidefulva, F. neogagates, F. microgyna, and F. rufa species groups, often in combination (Fisher and Cover 2007). Reproductives were found in a nest in August (Mackay and Mackay 2002).

Identification
The metanotal impression of this species is deep, the head is usually broader than long, the eyes of the majors fail to reach the sides of the head, and there are usually 1 - 4 hairs on the underside of the head. The hairs on the gaster are abundant, but are approximately as abundant (and of the same length) as the hairs on the pronotum. The length of the scape is less than or equal to the length of the head. (Mackay and Mackay 2002)

In Wisconsin this species is recognized by the shiny sides of the head and pronotum, and by the relatively long, curved, and abundant dorsal pilosity.

Distribution
Canada, Quebec. United States: northeastern US, west to North Dakota and south to New Mexico.

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

Habitat
In New Mexico (Mackay and Mackay 2002) - Aspen forests, disturbed areas.

Biology
This species is a member of a group of Formica species that were formerly placed in the subgenus Raptiformica. All species are facultative slavemakers, i.e., species which usually or often have slaves but can get along without them. The colony-founding female forces her way into a small colony of another species of Formica, somehow gets rid of its queen and workers and appropriates its nest and brood. The workers emerging from this brood accept the intruding queen as their own. The enslaved species belong to the Formica neogagates, F. fusca, and F. pallidefulva species groups. When the workers of the slave-making species have become numerous enough, they start raiding for more slaves.

This slave-maker enslaves colonies of Formica difficilis, Formica fusca, Formica  pallidefulva and Formica podzolica, among others. For example, at one site in the prairies of Missouri, a F. pergandei nest contained a mélange of six slave species including (in order of decreasing relative abundance) Formica pallidefulva, Formica subsericea, Formica biophilica, Formica dolosa, Formica incerta and Formica obscuriventris, certainly the most species-rich, naturally occurring ant colony on record (Trager et al., 2007)!

While F. pergandei is the most common slavemaker in central Wisconsin, Formica subintegra is more common than F. pergandei in western Pennsylvania, at least in highly-managed open woodland habitats (mown lawns and gardens).

Slave Making
Formica pergandei is known to inslave the following species:

Nomenclature

 *  pergandei. Formica pergandei Emery, 1893i: 646, pl. 22, fig. 1 (w.) U.S.A. Combination in F. (Raptiformica): Emery, 1925b: 259. Junior synonym of subintegra: Wilson & Brown, 1955: 120. Revived from synonymy and senior synonym of sublucida: Buren, 1968a: 28. See also: Snelling, R.R. & Buren, 1985: 72.
 * sublucida. Formica sublucida Creighton, 1950a: 472 (w.q.) U.S.A. [First available use of Formica sanguinea subsp. rubicunda var. sublucida Wheeler, W.M. 1913f: 408; unavailable name.] Junior synonym of subintegra: Wilson & Brown, 1955: 120; of pergandei: Buren, 1968a: 28.