Myrmecina arcuata

Nothing is known about the biology of .

Identification
Okido, Ogata, and Hosoishi (2020) - The relative length of the antennal scape, the shape of the mesosoma without the eumetanotal spine, and the shape of the first gastral tergum, are similar in M. arcuata, Myrmecina modesta and Myrmecina subarmata. Among these species, M. arcuata can be distinguished by its elongate propodeal spine.

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

Nomenclature

 * . Myrmecina arcuata Okido, Ogata & Hosoishsi, 2020: 15, fig. 3 (w.) PHILIPPINES.

Worker
Holotype TL 2.62, HL 0.66, HW 0.59, CI 90, SL 0.56, SI 95, PW 0.432, ML 0.72.

Head subrectangular, slightly longer than 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 blunt tooth; small teeth unclear. Dorsal surface of clypeus not slightly concave; median portion of anterior margin projected with three median processes that are very small; lateral portion simple, lacking sharp ridge in front of antennal insertions. Anterior dorsal surface of labrum with paired denticles very small. Frontal carinae virtually absent, indistinguishable from rugae on dorsum of head. Eyes large and convex with maximum diameter 0.10 mm, with 6 ommatidia in the longest row; malar space slightly twice as long as diameter of eye or shorter in profile; distance between occipital margin and posterior margin of eye four times as long as diameter of eye. Antennal scape long, extending beyond posterolateral corner of head; antennal flange developed.

Dorsal outline of mesosoma convex in profile. Pronotum without denticles; anterior portion marginate; anterior ventrolateral portion angulate. Furrow between pronotum and mesoepisternal projection narrow. Eumetanotal spine absent. Propodeal spine elongate, 1.5 times as long as broad at base, extending over vertical posteriormost limit of propodeum in profile. Propodeal lobe low. Propodeal spiracle large, situated near posterior margin of propodeum, distance between posterior margin of spiracle and posterior margin of propodeum slightly longer than diameter of spiracle. Petiole long, longer than high in profile, and longer than broad in dorsal view; dorsal crest absent; subpetiolar process absent. Postpetiole slightly broader than petiole in dorsal view; anterodorsal outline slightly convex in profile; ventral outline projected with acute anterior apex.

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

Head with straight rugae on dorsum which are distinct and longitudinal; ventrolateral portion with deep straight rugae. Clypeus smooth and shining. Mesosoma with deep straight rugae longitudinally. Forecoxa smooth and shining. Petiole and postpetiole with a few distinct rugae. First gastral segment smooth and shining. Head with relatively sparse and long pilosity on dorsum. Mesosoma with relatively sparse and long pilosity on dorsum, hairs of pronotum shorter than propodeal spine. Petiole without hairs on ventral surface. Postpetiole with 1-2 hairs on ventral surface. Body black or dark reddish brown, forecoxae reddish brown, mandibles, antennae and legs yellowish brown.

Type Material
Holotype worker, PHILIPPINES: Luzon, Lagunas, Mt. Banahaw, 24. xi. 1995, 700 m, (I. Löbl).