Myrmoteras concolor Bui, Eguchi & Yamane, 2013, sp. nov.

Myrmoteras concolor sp. nov.

(Figs. 1 –C, 4)

Holotype. Worker from Eastern Thailand, Chanthaburi Province, Khao Soi Dao WS, rain forest, 4 vi 2001, leg. Sk. Yamane (TH01-SKY-47) [THNHM].

Paratypes. 14 workers and 2 winged queens from same colony as holotype; 15 workers and 2 males, same locality, 4 vi 2001, leg. Sk. Yamane (TH01-SKY-53); 6 workers, same locality, waterfall, 13 v 2008, leg. W. Jaitrong (4 workers from WJT06-E020, 2 from WJT08-E021); 3 workers, same locality, 3 vi 2001, leg. K. Eguchi (Eg01-TH-029); 2 workers, same locality, 4 vi 2001, leg. K. Eguchi (Eg01-TH-048); 1 worker, same locality, 4 vi 2001, leg. K. Eguchi (Eg01-TH-057) [ACEG, MHNG, SKYC, THNHM, VNMN].

Non-type material examined. Thailand: 1 worker, Loei Prov., Phu Luang WS, 18 v 2007, leg. S. Hasin (SH07-TH); 3 workers, Chachoengsao Prov., Khao Ang Reu Nai, Bo Tong station, 29–30 xii 2002, leg. W. Jaitrong (WJT-TH-THNHM-I 20023537, 20023689); 2 workers, Nakhonratchasima prov., Khao Yai NP, TRF, 31 v 2000, leg. Sk. Yamane (TH00-SKY-47); 1 worker, same locality, 29 v 2000, leg. S. Hasin.

Worker measurements and indices. TL 4.0– 4.5, HL 1.08– 1.15 (1.11), HW 1.08– 1.13 (1.11), EL 0.65– 0.71 (0.68), ML 1.38– 1.46 (1.42), SL 1.31– 1.38 (1.34), PrW 0.65– 0.71 (0.68), HfL 1.38– 1.56 (1.44), CI 98 –104 (101), SI 117– 122 (120). (Holotype and 5 non-type workers were measured.)

Worker description. Body and coxae dark-brown; mandible and legs (except coxae) lighter than body. Body with erect hairs; dorsum of head, pronotum and gastral tergites without pubescence, or at most with very short pubescence (distance between appressed hairs longer than the hairs). Clypeus and frons mainly rugoso-punctate; vertex of head (including occipital lobe) smooth; frontal sulcus faint, reaching the middle ocellus; anterior clypeal margin concave; mandible with 9 teeth that reduce in size from the apical to basal teeth; two denticles present between first and second teeth; palp formula 6,4; orbital groove absent; scape a little shorter than funicular segments combined; funicular segments each longer than broad. Pronotum in lateral view flattened dorsally; anteriormost part of pronotum transversely rugose, and its remainder part smooth or faintly rugoso-punctate; dorsum of mesonotum longitudinally or irregularly rugose; side of mesonotum irregularly rugose; mesopleuron, metapleuron and lateral face of propodeum smooth; dorsum of propodeum weakly rugoso-punctate; propodeum in lateral view roundly convex posterodorsad. Petiolar node in lateral view with vertical anterior face and steep posterior slope; ventral outline of petiole beneath the node slightly sinuate or almost straight.

Remarks. This species is similar to M. binghamii. However, it is distinguished from the latter by the much sparser pubescence on the gastral tergites, especially on second tergite, and dark-colored coxae.

Distribution. Thailand.