Trichomyrmex

The ant genus Trichomyrmex Mayr, 1865 is a small genus in the subfamily Myrmicinae. The genus is known from the Palearctic, the Afrotropical, the Malagasy, the Nearctic, Neotropical, Oriental and Australian regions. Most species nest directly in the ground, or under stones, or in rotten wood, or sometimes in more specialized habitats such as termitaries. The described species are considered either granivorous (Trichomyrmex abyssinicus, Trichomyrmex chobauti), or are predators or scavengers (Trichomyrmex destructor, Trichomyrmex mayri). (Sharaf et al. 2016)

Identification
Sharaf et al. (2016) - Workers of Trichomyrmex can be recognized by the following characters: usually polymorphic; antennae 12-segmented, either lacking an apical club or with a club of 3 or 4 segments (usually 3, e.g., species of the Trichomyrmex destructor-group); masticatory margin of mandibles armed with 3–4 teeth, when 4 the basalmost tooth is reduced to an offset denticle or blunt angle; palp formula 2,2; scrobes absent; median portion of clypeus is short and does not project anteromedially; the anterior clypeal margin is only feebly convex to concave; clypeus usually with a distinct unpaired seta located at the midpoint of the anterior margin; the antennal fossae are surrounded by fine and curved striolae; metanotal groove impressed; propodeum unarmed, with transversely sculptured dorsum; propodeal spiracle usually circular to subcircular (vertical ellipse or short slit in Trichomyrmex abyssinicus; sting absent.

Biology
Sharaf et al. (2016) - Among the nine species of the genus Trichomyrmex reported from the Arabian Peninsula, T. mayri and Trichomyrmex destructor are the most abundant ones. However, T. mayri is the most successfully distributed species, since it has the ability to establish itself in a broad range of habitats, including desert and agricultural, wild and urban, pristine and disturbed sites (Collingwood 1985; Collingwood & Agosti 1996; Collingwood et al. 1997, 2011). These observations agree with Collingwood et al. (2004) and Sharaf et al. (in press) on Socotra, where T. mayri has a broad distributional range on the Archipelago, occurring in different habitats. The species is also recorded from different localities in Egypt, including the Sinai and Nile Delta (Sharaf 2006). The two species are recorded here for the first time from Qatar, which is not surprising, especially under the intensive urbanization that has occurred recently (UNCSD 2004).

Nomenclature

 *  TRICHOMYRMEX  [Myrmicinae: Crematogastrini]
 * Trichomyrmex Mayr, 1865: 19. Type-species: Trichomyrmex rogeri, by monotypy.
 * Trichomyrmex junior synonym of Monomorium: Ettershank, 1966: 82; Bolton, 1987: 296.
 * Trichomyrmex revived from synonymy of Monomorium: Ward et al., 2014: 16.
 * EQUESTRIMESSOR [junior synonym of Trichomyrmex]
 * Equestrimessor Santschi, 1919d: 92 [as subgenus of Monomorium]. Type-species: Holcomyrmex chobauti, by subsequent designation of Donisthorpe, 1943f: 644.
 * Equestrimessor junior synonym of Monomorium: Ettershank, 1966: 82; see also discussion in Bolton, 1987: 297.
 * [Ward et al. (2014) transferred the type species of Equestrimessor to Trichomyrmex but did not formally synonimise Equestrimessor under Trichomyrmex although this was implied.]
 *  EQUESSIMESSOR [unavailable name]
 * Equessimessor Santschi, 1936a: 32, incorrect subsequent spelling of Equestrimessor.
 * HOLCOMYRMEX [junior synonym of Trichomyrmex]
 * Holcomyrmex Mayr, 1879: 671. Type-species: Holcomyrmex scabriceps, by subsequent designation of Bingham, 1903: 280.
 * [Holcomyrmex Smith, F. 1873: ix. Nomen nudum, attributed to Mayr.]
 * Holcomyrmex junior synonym of Monomorium: Emery, 1908h: 667.
 * Holcomyrmex revived from synonymy as subgenus of Monomorium: Emery, 1915i: 190.
 * Holcomyrmex junior synonym of Monomorium: Ettershank, 1966: 82; see also discussion in Bolton, 1987: 295.
 * Holcomyrmex junior synonym of Trichomyrmex: Ward et al., 2014: 16.
 * PARHOLCOMYRMEX [junior synonym of Trichomyrmex]
 * Parholcomyrmex Emery, 1915i: 190 [as subgenus of Monomorium]. Type-species: Myrmica gracillima (junior synonym of Atta destructor), by original designation.
 * Parholcomyrmex junior synonym of Monomorium: Ettershank, 1966: 82; Bolton, 1987: 296.
 * Parholcomyrmex junior synonym of Trichomyrmex: Ward et al., 2014: 16.
 * [ Paraholcomyrmex Emery, 1915i: 191; Forel, 1917: 242; incorrect subsequent spellings.]