Formica fukaii

Known from Japan, between 35 and 44°N, and China.

Identification
Seifert (2000) - All Japanese material, including four worker syntypes from MCZ Cambridge, labelled “Saitama, Japan Formica exsecta var. fukai Syntypes, MCZ Cotype 23247”, clearly differs from Formica exsecta and Formica mesasiatica by constant absence of setae from first (workers) or first and second gaster tergites (queens), by the reduced coxal pilosity, by the complete reduction of setae in median and caudal parts of clypeus, and by the frequent reduction of setae in the ocellar region. The frontal and gastral pubescence distance is extremely low in both workers and queens and achieves in the latter caste values not found in other species. Agosti gave as pubescence density on median part of second gaster tergite 2295 hairs/mm2 for a fukaii queen but only 1348 hairs/mm2 as upper extreme for eight measured exsecta queens. The complete reduction of standing promesonotal setae in the fukaii queens is another differential character.

Distribution based on Regional Taxon Lists
Palaearctic Region: China, Japan.

Nomenclature

 *  fukaii. Formica exsecta var. fukaii Wheeler, W.M. 1914a: 26 (w.) JAPAN. Kupyanskaya, 1990: 201 (q.m.). Raised to species: Sonobe & Dlussky, 1977: 23. [Misspelled as fukali by Emery, 1925b: 257 and as fukalii by Wu, 1990: 5.] See also: Seifert, 2000a: 533.

Worker
Seifert (2000) - Very large (CL 1481 ± 40, 1418-1548; CW 1413 ± 49, 1343-1486). Head shape similar to exsecta (CL/CW 1.048 ± 0.012, 1.025-1.063). Scape very long (SL/CL 1.046 ± 0.018, 1.018-1.071). Standing setae on clypeus restricted to the anterior part (ClySet 1.83 ± 0.39,1-2). Lateral semierect setae in the ocellar triangle rarely present (OceSet 33%). Eye hairs always strongly developed (EyeHL 28.5 ± 2.8, 25-34). Pubescence in the occellar triangle always very dense (sqrtPDF 4.02 ± 0.31, 3.65-4.90). Craniad profile of forecoxae only exceptionally with single apical setae (nCOXA 0.08 ± 0.29, 0-1). Lateral metapleuron and ventrolateral propodeum without standing setae (nMET 0.0 ± 0.0). Outer edge of the hind tibial flexor side hairy (nHTFL 7.20 ± 2.33, 1.0-10.0). First gaster tergite always without standing setae (TERG 2.75 ± 0.45, 2-3). Pubescence distance on first gaster tergite extremely low (sqrtPDG 3.93 ± 0.13, 3.68-4.16).

Queen
Seifert (2000) - Very large (CL 1672, CW 1707, ML 2948). Head broad (CL/CW 0.979), scape long (SL/CL 0.967). Clypeus only in anterior part with setae. Lateral semierect setae in the ocellar triangle absent. Eye hairs long and numerous (EyeHL 46). Pubescence in the occellar triangle extremely dense (sqrtPDF 3.11). Occipital corners of head only with short decumbent hairs (OccHD 15). Brilliance of dorsal head surface intermediate (GLANZ 2.0). Craniad profile of forecoxae without or only single apical setae (nCOXA 0-1). Promesonotum without standing setae (MnHL 0). Outer edge of the hind tibial flexor side with several setae (nHTFL 7.0). Semierect setae on gaster tergites beginning on the third tergite (TERG 3.0). Pubescence distance on first gaster tergite extremely low (sqrtPDG 3.23).

Type Material
Saitama, Japan. Syntypes 4 workers [investigated].