Myrmecina boltoni

Identification
Okido, Ogata, and Hosoishi (2020) - Similar to Myrmecina monticola by its simple petiole without a subpetiolar process or median longitudinal ridge, the relative length of the antennal scape, and a mesosoma with a eumetanotal spine. Myrmecina boltoni differs by its anterior clypeal margin a median paired process and a sculptured forecoxa.

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

Nomenclature

 * boltoni. Myrmecina boltoni Okido, Ogata & Hosoishsi, 2020: 25, fig. 8 (w.) INDONESIA.

Worker
Holotype. TL 3.87, HL 0.91, HW 0.88, CI 96, SL 0.87, SI 99, PW 0.59, ML 1.09. Paratype. TL 3.51-4.46, HL 0.84-1.08, HW 0.82-1.04, CI 93-100, SL 0.80-0.91, SI 88-100, PW 0.53-0.67, ML 1.04-1.22 (6 measured).

Head subrectangular, as long as broad in full-face view; median portion of occipital margin flattened or slightly concave; occipital corners rounded, not projected posteriorly. Masticatory margin of mandible bent at midlength (third small tooth or sixth tooth); apical tooth strong, third tooth robust, followed by 5 small teeth and a blunt basal tooth. Dorsal surface of clypeus concave; median portion of anterior margin slightly projected with two or four processes; lateral portion simple, lacking sharp ridge in front of antennal insertions. Anterior dorsal surface of labrum with paired small denticles distinctly, close to each other. Frontal carinae virtually absent, indistinguishable from rugae on dorsum of head. Eyes large and distinctly convex, varying in size with maximum diameter 0.11-0.16 mm and 5-10 ommatidia; malar space longer than diameter of eye in profile; distance between occipital margin and posterior margin of eye twice as long as diameter of eye or longer. Antennal scape long, extending beyond posterolateral corner of head; antennal flange fully developed.

Dorsal outline of mesosoma slightly convex in profile. Pronotum with small denticles but unclearly; anterior portion not marginate; anterior ventrolateral portion usually angulate, sometimes not angulate. Furrow between pronotum and mesoepisternal projection narrow, sometimes relatively broad. Eumetanotal spine long. Propodeal spine triangular, variable in length, not or just reaching vertical posteriormost limit of propodeum in profile; as long as broad at base or longer. Propodeal lobe low. Propodeal spiracle large, situated near base of propodeal spine, distance between posterior margin of spiracle and posterior margin of propodeum longer than diameter of spiracle. Petiole long, longer than high in profile, and slightly longer than broad in dorsal view; dorsal crest located at midlength in profile; subpetiolar process and median longitudinal ridge usually absent. Postpetiole slightly broader than petiole in dorsal view; dorsal outline flattened or slightly convex in profile; ventral outline slightly projected with two tops.

Anterior margin of gaster not concave in dorsal view; first gastral sternum simple without median longitudinal ridge.

Head with straight rugae distinctly; ventrolateral portion with also deep and straight rugae longitudinally but frequently smooth and shining. Clypeus smooth and shining. Mesosoma with thick rugae longitudinally. Forecoxa with transverse rugae. Petiole and postpetiole with longitudinal rugae. First gastral segment smooth and shining. Head with sparse and long pilosity on dorsum. Mesosoma with sparse and long pilosity on dorsum, hairs of pronotum longer than propodeal spine. Petiole with or without 1-4 hairs on ventral surface. Postpetiole with 2-8 hairs on ventral surface. Head, mesosoma, forecoxae, petiole and postpetiole black, gaster reddish brown, mandibles, antennae and legs yellowish brown to brown.

Type Material
Holotype worker, INDONESIA: Sulawesi, Utara, G. Muajat, 1780 m, 16. ix. 1985 (no collector’s name). Paratypes. 4 workers and 1 male with same data as holotype; 3 workers with same data as holotype but 25. i. 1985; 2 workers with same data as holotype but Summint area, ca 1780 m, 24. v. 1985.