Myrmoteras namphuong sp. nov.

(Fig. 6)

Type material. Holotype worker from Northern Vietnam, Lao Cai Province, Hoang Lien Son NP., Sa Pa Distr., Ban Khoang, secondary forest, stream-side, ca. 1700–1800 m alt., 27 iv 2002, leg. K. Eguchi (Eg02-VN-123) [VNMN]. Paratypes: 3 workers from the same colony as holotype [ACEG, SKYC, VNMN].

Worker measurements and indices. TL 4.5 –5.0, HL 1.25 –1.29 (1.26), HW 1.25 –1.31 (1.27), EL 0.75 –0.81 (0.77), ML 1.54–1.58 [1.56] (1.56), SL 1.48– 1.52 (1.51), PrW 0.77 –0.81 (0.79), HfL 1.73 –1.79 (1.77), CI 98–103 [100] (100), SI 116– 122 (119). (Holotype and 3 paratype workers were measured.)

Worker description. Frons and mesosoma dark brown; clypeus, vertex of head, petiole and gaster yellowishbrown; mandible and legs pale yellow. Body with sparse erect hairs; pubescence present near anterior margin of clypeus and frons. Clypeus smooth or slightly rugoso-punctate; frons mainly smooth, but area around antennal insertion slightly rugose; vertex of head (including occipital lobe) smooth; frontal sulcus very feeble, visible as a very short trace running backward until the middle of frons; anterior clypeal margin concave; mandible with 8 teeth that reduce in size from 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; mesonotum longer than high; dorsal part of mesonotum slightly rugoso-punctate transversely; lateral face of mesosoma more or less transversely rugose between pronotum and metathoracic tubercle, and obliquely rugose from the tubercle to propodeum; mesopleuron, metapleuron and lateral face of propodeum smooth; dorsum of propodeum smooth or slightly rugoso-punctate transversely; propodeum in lateral view roundly convex posterodorsally. Petiolar node in lateral view with vertical anterior face and steep posterior slope; ventral outline of petiole beneath the node slightly concave.

Etymology. The specific name is after a famous queen of an ancient Vietnamese dynasty.

Remarks. This beautiful species is separated from other Indo-Chinese congeners by the lack of pubescence on the gastral tergites, incomplete frontal sulcus, and yellow mandible and petiole.

Distribution. Vietnam.