Myrmecina asiatica

This species inhabits soil and litter.

Identification
Okido, Ogata, and Hosoishi (2020) - Myrmecina asiatica does not belong to any species complex. But in terms of the body size, the masticatory margin of the mandible, relative length of the antennal scape, the shape of first gastral tergum, and the body sculpture, the species is similar to Myrmecina sulawesiana. The similarity of those species does not always reflect the relationships, because the characters mentioned above tend to change independently. Although differences between these two species are subtle, M. asiatica can be distinguished from the latter by having small and circular eye comprising about 9 ommatidia. Some morphological characters of the species are variable, and the species is widely distributed in the Indo-Chinese and Indo-Malayan subregions. In the light of these facts, it may be possible that the species would be split into more than one species.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Malaysia. Oriental Region: Thailand. Palaearctic Region: China.

Nomenclature

 * . Myrmecina asiatica Okido, Ogata & Hosoishsi, 2020: 17, fig. 4 (w.) CHINA.

Worker
Holotype. TL 2.53, HL 0.59, HW 0.54, CI 92, SL 0.50, SI 91, PW 0.38, ML 0.64. Paratype. TL 2.51-2.68, HL 0.59-0.61, HW 0.54-0.56, CI 91-95, SL 0.50, SI 89-91, PW 0.37-0.39, ML 0.66-0.70 (5 measured).

Head subrectangular, slightly longer than broad, sometimes as long as broad in full-face view; median portion of occipital margin 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 basal tooth. Dorsal surface of clypeus not concave; median portion of anterior margin feebly projected with or without a median process; lateral portion simple, lacking sharp ridge in front of antennal insertions. Anterior dorsal surface of labrum with paired small denticles, which are usually well separated. Frontal carinae virtually absent, indistinguishable from rugae on dorsum of head. Eyes extremely small, varying in size with maximum diameter 0.06 mm and 7-11 ommatidia, circular, and moderately convex; malar space usually three times as long as diameter of eye or longer, but variable; distance between occipital margin and posterior margin of eye distinctly five times as long as diameter of eye or longer, but variable. Antennal scape short, just reaching posterolateral corner of head; antennal flange fully developed.

Dorsal outline of mesosoma slightly convex in profile. Pronotum without denticles; anterior portion incompletely marginate; anterior ventrolateral portion not angulate. Furrow between pronotum and mesoepisternal projection broad. Eumetanotal spine present but small, sometimes unclear. Propodeal spine triangular, variable in length, usually extending beyond, sometimes just reaching vertical posteriormost limit of propodeum in profile. Propodeal lobe low. Propodeal spiracle large, situated near posterior margin of propodeum, usually apart from margin by its diameter. Petiole short, as long as or slightly longer than high in profile, and slightly longer than broad in dorsal view; dorsal crest located at midlength in profile; subpetiolar process variously developed from weakly raised median longitudinal ridge to distinct projection. Postpetiole slightly broader than petiole in dorsal view; dorsal outline flattened or slightly convex in profile; ventral outline not or slightly projected rectangularly with acute anterior apex.

Anterior margin of gaster not concave in dorsal view.

Head with slightly waved or straight rugae, sometimes also punctured; ventrolateral portion usually with longitudinal rugae and/ or punctures, sometimes smooth and shining. Clypeus smooth and shining. Mesosoma with deep and longitudinal rugae with or without punctures. Forecoxa smooth and shining. Petiole and postpetiole usually with longitudinal rugae, sometimes with transverse or irregular rugae, or almost smooth and shining. First gastral segment smooth and shining. Head with dense and short pilosity on dorsum. Mesosoma with dense and short pilosity on dorsum, hairs of pronotum usually shorter than propodeal spine. Petiole without hairs on ventral surface. Postpetiole usually with 1-2 hairs on ventral surface. Head and mesosoma black, forecoxae reddish brown to yellowish brown, petiole, postpetiole and gaster black to reddish brown, mandibles, antennae and legs yellowish brown.

Type Material
Holotype worker, CHINA: Dahaoping, Gaoligongshan Mts., Tengchong Xian, Yunnan Prov., 10. x. 1996 (S. Nomura). Paratypes. 7 workers with same data as holotype.