Formica fukaii Wheeler, 1914

Seifert, Bernhard, 2000, A taxonomic revision of the ant subgenus Coptoformica Mueller, 1923 (Hymenoptera, Formicidae), Zoosystema 22 (3), pp. 517-568 : 533-534

Formica fukaii Wheeler, 1914

Formica exsecta var. fukai Wheeler, 1914

TYPE LOCALITY. — Saitama, Japan.

TYPE MATERIAL. — Syntypes 4 workers ( MCZ) [investigated].

GEOGRAPHIC ORIGIN OF THE MATERIAL STUDIED. — Numerically evaluated were five different samples with 12 workers and one queen from Japan.

DESCRIPTION

Worker

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

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).

TAXONOMIC COMMENTS AND

DIFFERENTIAL DIAGNOSIS

All Japanese material, including four worker syntypes from MCZ Cambridge, labelled “ Saitama, Japan Formica exsecta var. fukai Syntypes, MCZ Cotype 23247 ”, clearly differs from exsecta and 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/mm 2 for a fukaii queen but only 1348 hairs/mm 2 as upper extreme for eight measured exsecta queens. The complete reduction of standing promesonotal setae in the fukaii queens is another differential character. Hence, there is little doubt that fukaii represents an endemic Japanese species. It is distributed there between 35 and 44°N. The synonymisation of fukaii with mesasiatica as performed by Sonobe & Dlussky (1977) is clearly contradicted by setae counts and setae positions. These authors also gave some notes on the ecology of fukaii .