Nesomyrmex

Hita Garcia, Wiesel and Fischer (2013) - Nesomyrmex, formerly a subgenus of the large and almost cosmopolitan Leptothorax, was raised to genus in 2003 (Bolton, 2003) and 52 species can be encountered in the tropics and subtropics of the Neotropical, Malagasy and Afrotropical regions (Bolton, 2012). The biology of the genus is not well studied. Most species prefer arid habitats while a few live in rainforests. Generally, Nesomyrmex ants can nest either in the soil, as most South African species do, or in trees (Mbanyana & Roberson, 2008), often in pre-existing cavities.

Identification
Superficially, Nesomyrmex workers with a rounded propodeum that lacks spines can be confused with Monomorium, but can be distinguished by lacking the isolated median setae on the anterior clypeal margin. Those species of Nesomyrmex that have the propodeum armed or angulate, superficially resemble Tetramorium species, and can be separated from them mainly by the lateral portions of clypeus, which are not raised into a narrow ridge or shield-wall in front of the antennal insertions, unlike in Tetramorium. Nesomyrmex can also be confused with Cardiocondyla because the median portion of the clypeus extends over the mandibles in both genera. They are most easily distinguished by the shape of the postpetiole in dorsal view, which in Cardiocondyla is considerably broader than the petiolar node. In addition, the eyes of Cardiocondyla are in front of the midlength of the sides whereas in Nesomyrmex they are at the midlength. (Mbanyana and Robertson 2008)

Nesomyrmex species groups of the Afrotropical and Malagasy regions

Nomenclature

 *  NESOMYRMEX [Myrmicinae: Formicoxenini]
 * Nesomyrmex Wheeler, W.M. 1910a: 259. Type-species: Nesomyrmex clavipilis, by monotypy.
 * Nesomyrmex subgenus of Leptothorax: Emery, 1915g: 24; Wheeler, W.M. 1922a: 679; Smith, M.R. 1950: 30; Smith, M.R. 1951a: 816; Kempf, 1959c: 393; Brown, 1971a: 4; Kempf, 1972a: 133; Smith, D.R. 1979: 1391.
 * Nesomyrmex as genus: Francoeur & Loiselle, 1988b: 43 (possibly valid); Hölldobler & Wilson, 1990: 14 [junior synonyms of Nesomyrmex left under Leptothorax]; Jaffe, 1993: 11.
 * Nesomyrmex junior synonym of Goniothorax: Emery, 1924d: 249; Donisthorpe, 1943f: 674. [Incorrect procedure as Goniothorax is a junior homonym for which Nesomyrmex is the first available replacement name, see Smith, M.R. 1950: 30.]
 * Nesomyrmex senior synonym of Caulomyrma: Emery, 1915g: 24; Forel, 1915c: 364.
 * Nesomyrmex senior synonym of Limnomyrmex: Brown, 1971a: 4.
 * Nesomyrmex senior synonym of Meia: Bolton, 1994: 105.
 * Nesomyrmex junior synonym of Leptothorax: Bolton, 1982: 319.
 * Nesomyrmex revived from synonymy with status as genus and senior synonym of Caulomyrma, Ireneopone, Limnomyrmex, Meia, Tetramyrma: Bolton, 2003: 249, 272.
 * CAULOMYRMA [junior synonym of Nesomyrmex]
 * Caulomyrma Forel, 1914d: 233 [as subgenus of Leptothorax]. Type-species: Leptothorax echinatinodis, by original designation.
 * Caulomyrma junior synonym of Nesomyrmex: [Forel, 1915c: 364 (provisional synonym)]; Emery, 1915g: 24.
 * [Caulomyrma and Nesomyrmex junior synonyms of Goniothorax: Emery, 1924d: 249 (incorrect procedure as Goniothorax is a junior homonym for which Nesomyrmex is the first available replacement name; see Smith, M.R. 1950: 30).]
 * GONIOTHORAX [junior homonym, see Nesomyrmex]
 * Goniothorax Emery, 1896g: 58 (diagnosis in key) [as subgenus of Leptothorax]. Type-species: Leptothorax vicinus, by subsequent designation of Wheeler, W.M. 1911f: 164. [Junior homonym of Goniothorax Milne-Edwards, 1879: 103 (Crustacea).]
 * Goniothorax Emery senior synonym of Caulomyrma, Nesomyrmex: Emery, 1924d: 249. Nesomyrmex is oldest junior synonym of Goniothorax Emery and hence first available replacement name: Smith, M.R. 1950: 30.
 * [Goniothorax as subgenus of Leptothorax: Wheeler, W.M. 1910g: 139; Forel, 1917: 244; Wheeler, W.M. 1922a: 679; Emery, 1924d: 249; Creighton, 1950a: 259.]
 * IRENEOPONE [junior synonym of Nesomyrmex]
 * Ireneopone Donisthorpe, 1946d: 242. Type-species: Ireneopone gibber, by original designation.
 * Ireneopone junior synonym of Nesomyrmex: Bolton, 2003: 250, 272.
 * LIMNOMYRMEX [junior synonym of Nesomyrmex]
 * Limnomyrmex Arnold, 1948: 222. Type-species: Limnomyrmex stramineus, by original designation.
 * Limnomyrmex junior synonym of Nesomyrmex: Brown, 1971a: 4.
 * Limnomyrmex junior synonym of Leptothorax: Bolton, 1982: 319.
 * Limnomyrmex junior synonym of Nesomyrmex: Bolton, 2003: 250, 272.
 * MEIA [junior synonym of Nesomyrmex]
 * Meia Pagliano & Scaramozzino, 1990: 5. [Unnecessary replacement name for Goniothorax Emery, 1896g: 58; junior homonym of Goniothorax Milne-Edwards, 1879: 103 (Crustacea).]
 * [Nesomyrmex is the first available replacement name for Goniothorax Emery, therefore Meia is automatically a junior synonym of Nesomyrmex: Bolton, 1994: 105.]
 * TETRAMYRMA [junior synonym of Nesomyrmex]
 * Tetramyrma Forel, 1912m: 766 [as subgenus of Dilobocondyla]. Type-species: Dilobocondyla (Tetramyrma) braunsi, by monotypy.
 * Tetramyrma raised to genus: Forel, 1913a: 122.
 * Tetramyrma junior synonym of Leptothorax: Bolton, 1982: 319.
 * Tetramyrma junior synonym of Nesomyrmex: Bolton, 2003: 249, 272.