Lasius bicornis

Identification
Worker clear citron yellow. Funiculus segments not longer than broad; scape distinctly flattened. Outline of petiole characteristic: high, tapering dorsally with a deep emargination. Body hairs long, longest hairs nearly as long as maximum hind tibial width, sparse on dorsum of gaster where restricted to posterior borders of tergites; genal hairs sparse, scapes and tibiae bare. Length: 4.0-4.5 mm (Collingwood 1979).

Distribution
Central and South Europe from Pyrenees and Caucasus but also recorded from Himalayas (Kashmir), South Italy to Netherlands; uncommon (Collingwood 1979).

This taxon was described from Germany.

Biology
This species nests in rotten logs. Alatae have been taken in September (Poldi, 1962).

Nomenclature

 *  bicornis. Formica bicornis Foerster, 1850a: 41 (q.) GERMANY. Forel, 1874: 47 (w.); Forel, 1915d: 56 (m.). Combination in Lasius: Mayr, 1861: 51; in Formicina: Emery, 1916b: 242; Menozzi, 1918: 87; in Acanthomyops: Ruzsky, 1925b: 45; in Lasius (Chthonolasius): Ruzsky, 1914a: 61; Emery, 1925b: 232; Wilson, 1955a: 183. Subspecies of umbratus: Forel, 1874: 47; Emery & Forel, 1879: 453; Mayr, 1886d: 430; Forel, 1886f: 208; Forel, 1904b: 387; Bondroit, 1910: 485. Status as species: André, 1882b: 196; Ruzsky, 1902d: 15; Bondroit, 1912: 352; Emery, 1916b: 242; Bondroit, 1918: 34; Emery, 1922b: 13; Karavaiev, 1927c: 279; Stärcke, 1937: 55; Stitz, 1939: 302; Wilson, 1955a: 183; Bernard, 1967: 365; Kutter, 1977c: 231; Collingwood, 1982: 293; Seifert, 1988: 161; Atanassov & Dlussky, 1992: 251. Senior synonym of incisa: Smith, F. 1858b: 8; Emery, 1922b: 13; Seifert, 1988: 161; of microgyna: Vandel, 1926: 197; Wilson, 1955a: 183; of kashmirensis, neapolitana, oertzeni: Wilson, 1955a: 183.
 * incisa. Formica incisa Schenck, 1852: 63 (w.) GERMANY. Junior synonym of bicornis: Smith, F. 1858b: 8; Emery, 1922b: 13; Seifert, 1988: 161.
 * oertzeni. Lasius bicornis subsp. oertzeni Forel, 1910a: 26 (w.q.m.) GREECE. Combination in L. (Chthonolasius): Emery, 1925b: 233. Raised to species: Stärcke, 1937: 56. Junior synonym of bicornis: Wilson, 1955a: 183.
 * microgyna. Formicina microgyna Bondroit, 1918: 33, figs. 16, 17 (q.m.) FRANCE. Combination in Lasius (Chthonolasius): Emery, 1925b: 233. Subspecies of bicornis: Emery, 1925b: 233; Stärcke, 1937: 56. Junior synonym of bicornis: Vandel, 1926: 197; Wilson, 1955a: 183.
 * neapolitana. Lasius bicornis var. neapolitana Emery, 1922b: 13 (q.) ITALY. Junior synonym of bicornis: Wilson, 1955a: 183.
 * kashmirensis. Acanthomyops (Chthonolasius) bicornis subsp. kashmirensis Donisthorpe, 1930a: 225 (q.m.) INDIA. Junior synonym of bicornis: Wilson, 1955a: 183.