Pristomyrmex

Identification
From Wang (2003): Pristomrymrex belongs to the subfamily Myrmicinae. It possesses a raised transverse ridge or a few toothlike prominences on the dorsal labrum in all female castes, including workers, ergatoid queens, and queens. This character is also shared by the myrmicine genera Acanthomyrmex, Myrmecina, and Perissomyrmex. As a result, these four living genera are grouped together in the tribe Myrmecinini (Bolton, 1994, 1995, personal communication; Brown, 1971). Pristomyrmex is unique in the tribe because it is the only genus possessing 11 antennal segments in all three female castes and 12 segments in the male.

Distribution
From Wang (2003): Pristomymrex occurs primarily in the Oriental region, but six endemic species are present in the eastern rainforest of Australia and five endemic species in Africa. In addition, in Mauritius there are three native species, one of which also occurs on Reunion Island. Lastly, one species, Pristomyrmex punctatus, has invaded temperate China, Korea, and Japan. This species has also been detected at two entry ports in the United States and thus shows potential for spread via human commercial actions.

Biology
From Wang (2003): Most species dwell in the rainforest, foraging as predators or scavengers. An Asian species, Pristomyrmex punctatus, however, occurs in open and disturbed habitats (e.g., bare hills, agricultural areas, and beaches). These ants prefer to nest in soil, litter, or rotten wood; in rotten parts of living trees; in dead standing trees; or around plant roots.

Pristomyrmex is of great interest because it exhibits several unusual biological and evolutionary phenomena. The absence of morphologically normal queens and reproduction primarily by unmated workers in P. punctatus {=P. pungens) is a highly unusual life history in the Formicidae. Ergatoid queens, a special wingless female caste morphologically intermediate between the queen and the worker, are present in at least four species: Pristomyrmex punctatus, Pristomyrmex africanus, Pristomyrmex wheeleri, and Pristomyrmex mandibularis; two of them (P. africanus and P. wheeleri) possess both queen and ergatoid queen castes.

Simulating death, slowness of movement, and nocturnal foraging has been recorded in Pristomyrmex (Donisthorpe, 1946; Taylor, 1965; Weber, 1941). Colony size varies greatly among species, ranging from about a dozen to several thousand workers (Donisthorpe, 1946; Itow et al, 1984; Mann, 1919; Taylor, 1965, 1968).

Nomenclature

 *  PRISTOMYRMEX [Myrmicinae: Myrmecinini]
 * Pristomyrmex Mayr, 1866b: 903. Type-species: Pristomyrmex pungens, by monotypy.
 * Pristomyrmex senior synonym of Odontomyrmex: Mann, 1919: 341; Emery, 1924d: 233.
 * Pristomyrmex senior synonym of Hylidris: Brown, 1953c: 9.
 * Pristomyrmex senior synonym of Dodous: Brown, 1971a: 3.
 * DODOUS [junior synonym of Pristomyrmex]
 * Dodous Donisthorpe, 1946f: 145. Type-species: Dodous trispinosus, by original designation.
 * Dodous junior synonym of Pristomyrmex: Brown, 1971a: 3.
 * HYLIDRIS [junior synonym of Pristomyrmex]
 * Hylidris Weber, 1941a: 190. Type-species: Hylidris myersi (junior synonym of Pristomyrmex africanus), by original designation.
 * Hylidris junior synonym of Pristomyrmex: Brown, 1953c: 9.
 * ODONTOMYRMEX [junior synonym of Pristomyrmex]
 * Odontomyrmex André, 1905: 207. Type-species: Odontomyrmex quadridentatus, by monotypy.
 * Odontomyrmex subgenus of Pristomyrmex: Forel, 1917: 244; Wheeler, W.M. 1922a: 682.
 * Odontomyrmex junior synonym of Pristomyrmex: Mann, 1919: 341; Emery, 1924d: 233; Taylor, 1965b: 35; Bolton, 1981b: 282.