Myrmecina dechai

Identification
Okido, Ogata, and Hosoishi (2020) - Myrmecina dechai does not belong to any species complex. But in terms of the mesosoma with transverse rugae and relative length of the antennal scape, M. dechai is similar to Myrmecina poringensis. The similarity of those species does not always reflect the relationships, because the characters mentioned above tend to change independently. Among those species, M. dechai can be distinguished from the remains by having the triangular propodeal spine pointing backward.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand.

Nomenclature

 * . Myrmecina dechai Okido, Ogata & Hosoishsi, 2020: 34, fig. 13 (w.) THAILAND.

Worker
Holotype. TL 2.62, HL 0.59, HW 0.62, CI 105, SL 0.46, SI 74, PW 0.43, ML 0.67. Paratype. TL 2.68-2.69, HL 0.61-0.62, HW 0.62, CI 100-103, SL 0.46-0.48, SI 74-77, PW 0.42, ML 0.59-0.67 (2 measured).

Worker. Head subrectangular, as long as or slightly longer than broad in full-face view; median portion of occipital margin flattened; 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 not concave; median portion of anterior margin slightly projected with a small median process or three processes; lateral portion simple, lacking sharp ridge in front of antennal insertions. Anterior dorsal surface of labrum with paired small denticles distinctly, which are relatively well separated. Frontal carinae virtually absent, indistinguishable from rugae on dorsum of head. Eyes small and usually convex moderately, varying in size with maximum diameter 0.07-0.08 mm and 12-13 ommatidia; malar space 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 short, not reaching posterolateral corner of head; antennal flange weakly developed.

Dorsal outline of mesosoma convex in profile. Pronotum without denticles on dorsolateral portion; anterior portion marginate; anterior ventrolateral portion not angulate. Furrow between pronotum and mesoepisternal projection usually broad sometimes narrow. Eumetanotal spine present but small. Propodeal spine triangular, as long as broad at base, feebly extending over vertical posteriormost limit of propodeum in profile; tips directing outward in dorsal view. Propodeal lobe low. Propodeal spiracle small, situated near posterior margin of propodeum, distance between posterior margin of spiracle and posterior margin of propodeum variable, as long as diameter of spiracle or longer. Petiole short, as long as high in profile, slightly longer than broad in dorsal view; dorsal crest absent; subpetiolar process absent. Postpetiole slightly broader than petiole in dorsal view; dorsal outline flattened in profile; ventral outline slightly projected rectangularly with acute anterior apex.

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

Head weakly punctured with longitudinal rugae diverging posteriorly on occipital portion, and transverse rugae running along occipital carina; ventrolateral portion with longitudinal rugae weakly, but shining. Clypeus smooth and shining. Mesosoma weakly punctured with transverse rugae on anterior portion, and longitudinal rugae on posterior portion. Forecoxa almost smooth and shining. Petiole and postpetiole with distinct longitudinal rugae. 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 as long as propodeal spine. Petiole without hairs on ventral surface. Postpetiole with 2 hairs on ventral surface. Body and forecoxae black to reddish brown, mandibles, antennae and legs yellowish brown.

Type Material
Holotype worker, THAILAND: Kaeng Krachan N. P., 17. xi. 85 (I. Löbl & D. Burckhardt). Paratypes. 2 workers with same data as holotype; 2 workers with same data as holotype but 19. xi. 85.