Formica nana Jerdon

This taxon is not in use as it is currently considered to be a junior synonym of Tapinoma melanocephalum.

Nomenclature

 * nana. Formica nana Jerdon, 1851: 125 (w.) INDIA (Karnataka).
 * Type-material: syntype workers (number not stated).
 * Type-locality: India: Mysore (“found in all parts of India and is very abundant in Mysore”) (T.C. Jerdon).
 * Type-depository: unknown (no material known to exist).
 * [Duplicated in Jerdon, 1854b: 108.]
 * [Junior primary homonym of Formica nana Latreille, 1802c: 263 (Emery, 1921a: 26; Bolton, 1995b: 401).]
 * Status as species: Smith, F. 1858b: 15; Mayr, 1863: 418; Smith, F. 1871a: 303.
 * Junior synonym of melanocephalum: Emery, 1892b: 166; Dalla Torre, 1893: 165; Forel, 1895b: 109; Forel, 1895e: 472; Pergande, 1896: 870; Forel, 1899c: 101; Wheeler, W.M. 1908a: 150; Emery, 1913a: 41; Wheeler, W.M. 1919c: 275; Wheeler, W.M. 1919e: 100; Wheeler, W.M. 1922a: 925; Borgmeier, 1923: 101; Creighton, 1950a: 352; Smith, M.R. 1954c: 10; Smith, D.R. 1979: 1421; Shattuck, 1994: 148; Bolton, 1995b: 401; Tiwari, 1999: 83; Zhou, 2001b: 150; Radchenko, 2016: 92; Guerrero, 2018: 499.
 * Replacement name: Tapinoma jerdoni Seifert, 2022: 39. [Unavailable name (proposed in synonymy of T. melanocephalum (Fabricius, 1793: 353)).]

Taxonomic Notes
Seifert (2022) proposed the name Tapinoma jerdoni as a new replacement name for Formica nana Jerdon (1851) (which is a junior primary homonym of Formica nana Latreille (1802)). He states: Tapinoma jerdoni is proposed here as new replacement name for Formica nana (JERDON, 1851) that is a junior primary homonym of Formica nana (LATREILLE, 1802) that belongs to the subfamily Myrmicinae. Formica nana JERDON has been described from Mysore (India). Its original description reads as follows: “Worker, length not 1/12 inch (= 2.1 mm); eyes anterior, thorax wide; abdomen long, elliptical; head and thorax brown; antennae legs, and abdomen pale whity brown. This very minute species is found in all parts of India and is very abundant in Mysore; from its very small size is noticed with difficulty. It feeds on flowers and vegetable secretion.” This description strongly suggests that Tapinoma jerdoni nom. nov. belongs to one of the two species of the Ghost Ant. Its synonymization with T. melanocephalum proposed here is based on the fact that it is globally by far the most abundant species, that it is known from India and that no counterevidence is possible due to the absence of types.

However, as Tapinoma jerdoni was proposed in synonymy with Tapinoma melanocephalum, the name is unavailable (see ICZN Article 11.6. Publication as a synonym: A name which when first published in an available work was treated as a junior synonym of a name then used as valid is not thereby made available). Additionally, because of the age of these names, the ICZN requires prevailing usage be maintained until a ruling by the Commission has been made (ICZN Article 23.9.5. When an author discovers that a species-group name in use is a junior primary homonym [Art. 53.3] of another species-group name also in use, but the names apply to taxa not considered congeneric after 1899, the author must not automatically replace the junior homonym; the case should be referred to the Commission for a ruling under the plenary power and meanwhile prevailing usage of both names is to be maintained [Art. 82].) Thus the name Tapinoma jerdoni is unavailable and cannot be used for this taxon.