Myrmecina tridentata

The species inhabits the soil.

Identification
Okido, Ogata, and Hosoishi (2020) - A member of the Myrmecina spinosa complex. Among these species, Myrmecina spinosa and M. tridentata are distinguished by a concave anterior-margin of the first gastral tergum, bent masticatory margin of the mandible, and a propodeal spine extending backward. These two species differ by the sculpture on their head and the mesosoma; M. spinosa with straight and longitudinal rugae and M. tridentata with wavy and irregular, or transverse, rugae

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

Nomenclature

 * . Myrmecina tridentata Okido, Ogata & Hosoishsi, 2020: 99, fig. 46 (w.q.) MALAYSIA.

Worker
Holotype worker. TL 3.34, HL 0.86, HW 0.78, CI 91, SL 0.77, SI 98, PW 0.62, ML 0.93. Paratype workers. TL 3.28-3.51, HL 0.84-0.94, HW 0.78-0.83, CI 87-93, SL 0.74-0.82, SI 94-100, PW 0.62-0.67, ML 0.91-0.99 (5 measured).

Occipital margin strongly concave in full-face view; occipital corners projected posteriorly. Masticatory margin of mandible bent at midlength (third small tooth or sixth tooth); apical tooth strong, third tooth acute, followed by 5 small but distinct teeth and a stout basal tooth bearing blunt apex. Dorsal surface of clypeus concave; median portion of anterior margin projected, usually with three distinct processes; lateral portion simple, lacking sharp ridge in front of antennal insertions. Anterior dorsal surface of labrum with paired small denticles distinctly. Frontal carinae virtually absent, indistinguishable from rugae on dorsum of head. Eyes mediumsized, varying in size with maximum diameter 0.13-0.14 mm and 7-8 ommatidia. Antennal scape short, just reaching posterolateral corner of head; antennal flange weakly developed.

Dorsal outline of mesosoma convex in profile. Pronotum with two or four denticles on anterior dorsolateral portion in dorsal view but frequently unclear; anterior ventrolateral portion with denticle directing forward and downward. Eumetanotal spine triangular distinctly. Propodeal spine elongate, abruptly curved upward at their shafts but varying, distinctly extending over vertical posteriormost limit of propodeum in profile; tips curved outward in dorsal view. Propodeal lobe raised. Propodeal spiracle situated near base of propodeal spine, distance between posterior margin of spiracle and posterior margin of propodeum slightly longer than diameter of spiracle. Petiole long; small dorsal crest located at midlength in profile; subpetiolar process triangular; ventral outline slightly convex or flattened. Postpetiole almost as broad as petiole in dorsal view; lateral margin straight; lateral portion not marginated; dorsal outline slightly convex or almost flattened in profile; ventral outline projected at anterior portion.

Anterior margin of gaster concave in dorsal view;

Head usually with irregular rugae which are wavy, sometimes with longitudinal or parallel rugae; ventrolateral portion marginated on behind eyes in profile, with longitudinal rugae. Mandibles sometimes with small yellow spots on dorsal surface but varying and unclear. Clypeus smooth and shining. Mesosoma with irregular rugae which are wavy, sometimes with transverse (forming “U”-shape) rugae lateral portion with irregular rugae which are wavy, rarely with longitudinal rugae. Petiole and postpetiole with a few longitudinal rugae. First gastral tergum smooth and shining. Head with long pilosity on dorsum. Mesosoma with long pilosity on dorsum, hairs of pronotum usually as long as broad of apical second segment of antenna. Head, mesosoma, petiole and postpetiole black, legs yellowish brown, forecoxae varying from reddish brown to black, gaster reddish brown.

Type Material
Holotype worker, MALAYSIA: Sepilok, Sabah, Borneo, 14. viii. 1981 (K. Masuko). Paratypes. 20 workers and 1 queen (dealate) with same data as holotype (, KUEC, ).