Acanthomyrmex minus

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia.

Nomenclature

 *  minus. Acanthomyrmex minus Terayama, Ito & Gobin, 1998: 259, figs. 7-12, 22-24 (s.w.q.) INDONESIA (Sumatra).

Worker
Major. (holotype). HL 1.58 mm; HW 1.60 mm; SL 0.63 mm; CI 101; SI 39;WL 0.65 mm; PL 0.35 mm; PH 0.28 mm; DPW 0.26 mm; PPL 0.20 mm; PPH 0.28 mm; PPW 0.25 mm; TL 2.8 mm.

Head as long as wide, with weakly convex posterior margin in full face view; posterior margin very slightly notched medially; median furrow shallow, and recognized in posterior 2/5 of frons and vertex; frons and vertex smooth, without hairs; gena with shallow punctures moderately; shallow punctures also present near frontal carina. Mandible smooth, without any tooth. Anterior margin of clypeus straight, wihout a median projecting lobe. Antennal scape broadest at posterior 1/ 5 of its length, with about 10 erect hairs; 2nd segment slightly longer than wide; 3rd to 9th segments each 0.5 X as long as wide. Antennal scrobe moderately developed, but without funicular scrobe. Eye 0.10 mm in diameter.

Pro- and mesonotum with large punctures which are ca. 0.05 mm. Propodeal spine 0.24 mm long, turned to the posterior portion; declivitous surface subopaque.

Petiole longer than high, with acute triangular node in profile; posterodorsal margin with a pair of erect hairs; lateral petiolar hairs absent; in posterior view, node rectangular, with parallel sides and straight dorsal margin. Postpetiole rectangular, 0.76 X as long as wide in profile; 2 pairs of dorsal hairs and a pair of lateral hairs present; in dorsal view, 0.70Xas long as wide, with slightly concave anterior and straight dorsal margins.

Gaster smooth and impunctate, without hairs.

Body reddish brown; mandibles dark brown; antennae and legs yellowish brown.

Minor. HL 0.73 mm; HW 0.90 mm; SL 0.60 mm; CI 123; SI 67; WL 0.80 mm; PL 0.30 mm; PH 0.24 mm; DPW 0.18 mm; PPL 0.18 mm; PPH 0.23 mm; PPW 0.20 mm; TL 2.5 mm.

Head wider than long, with feebly concave posterior margin in full face view; frons and vertex with large coarse punctures which are ca. 0.06 mm in diameter. Mandible largely smooth. Antennal scape with about 10 erect hairs; 2nd segment slightly longer than wide; 3rd to 9th segments each 0.5 X as long as wide. Clypeus with 2 longitudinal rugae; median clypeal lobes feebly developed; clypeal index 84. Eye 0.11 mm in diameter.

Alitrunk with convex dorsal outline in profile; pro- and mesonotum punctate as in head; pronotal spine 0.13 mm long; propodeal spine thin and straight, 0.28 mm long. Petiole 1.25 X as long as high, with a pair of posterodorsal hairs; lateral petiolar hairs absent; in posterior view, node with parallel sides and straight dorsal margin. Postpetiole 0.78 X as long as high, with straight dorsal margin in profile; dorsum with 2 pairs of erect hairs; lateral postpetiolar hairs present; in dorsal view, 0.76 Xas long as wide.

Gaster smooth and shining, without hairs.

Body reddish brown, gaster slightly darker; antennae reddish brown; mandibles and legs brown.

Queen
Ergatoid. HL 0.90 mm; HW 1.08 mm; SL 0.65 mm; CI 119; SI 60; WL 0.83 mm; PL 0.35 mm; PH ; 0.26 mm; DPW 0.21 mm; PPL 0.18 mm; PPH 0.28 mm; PPW 0.24 mm; TL 2.5 mm.

Head wider than long, with concave posterior margin in full face view; frons and vertex with shallow punctures sparsely; the punctures ca. 0.05 mm in diameter, and separated by 1.5-2.0 X their own diameters; interspaces smooth. Mandible large, without tooth as in major worker. Anterior margin of clypeus straight, without distinct teeth. Antennal scape with about 10 erect hairs; 2nd segment longer tthan wide; 3rd to 9th segments each wider than long. Eye 0.11 mm in diameter.

Alitrunk, petiole, postpetiole, and gaster as in major worker.

Body reddish brown; mandibles, antennae and legs yellowish brown.

Type Material
Holotype. Major worker, Vlu Gadut, Padang, Sumatra, Indonesia, 28.III.1997, F. Ito leg. Paratypes. 1 major worker, 17 minor workers, 1 ergatoid queen, same colony as holotype; 8 minor workers, 1 ergatoid queen, same data as holotype.

Etymology
The specific epithet is named after the small body size of major workers.