Platythyrea janyai

The type series and all material examined of P. janyai were collected from small dead wood on the forest floor in lowland rainforests.

Identification
Phengsi et al. (2018) - Platythyrea janyai and Platythyrea clypeata are very similar in general appearance as they share the following characteristics: body reddish brown; frontal lobe narrow; frontal carinae closely spaced and strongly narrowed posteriorly; mandible triangular, its masticatory margin with a large apical tooth, followed by 9–10 smaller teeth, large and smaller teeth alternating; propodeal spiracle opening elliptical; in dorsal view posterior margin of petiole convex without spines. However, Platythyrea janyai can be easily separated from Platythyrea clypeata by the following characteristics: head relatively shorter (CI 72–74 in Platythyrea janyai; CI 61–69 in Platythyrea clypeata); eye clearly larger (EL 0.20 mm with eleven ommatidia on longest axis in Platythyrea janyai; EL 0.10 mm with five ommatidia on longest axis in Platythyrea clypeata); eye convex (flat in Platythyrea clypeata); dorsum and lateral face of head finely micropunctate without foveae (finely punctate with dense shallow foveae in Platythyrea clypeata); in profile view petiole clearly longer than high and in dorsal view node of petiole anteriorly as broad as posteriorly (slightly longer than high and in dorsal view node of petiole slightly narrower posteriorly in Platythyrea clypeata); ventral outline of petiole weakly convex (feebly concave in Platythyrea clypeata). No overlap is observed in HW / SL between the species. Platythyrea janyai (Malay Peninsula: S Thailand and W. Malaysia) is distinctly allopatric with Platythyrea clypeata (known from from Sri Lanka, Vietnam, Laos, and east Thailand).

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

Nomenclature

 *  janyai. Platythyrea janyai Phengsi, Jaitrong, Ruangsittichai & Khachonpisitsak, 2018: 89 (w.) THAILAND.

Worker
Holotype: TL 6.63 mm; HL 1.42 mm; HW 1.06 mm; SL 1.39 mm; EL 0.20 mm; WL 2.21 mm; PL 0.73 mm; PH 0.53 mm; PW 0.40 mm; CI 74, EI 18, SI 131. Paratypes (n = 3). TL 6.67-6.96 mm; HL 1.45 mm; HW 1.06 mm; SL 1.42 mm; EL 0.20 mm; WL 2.31 mm; PL 0.79 mm; PH 0.53 mm; PW 0.40 mm; CI 72, EI 18, SI 134.

Head. Head in full-face view subrectangular, clearly longer than broad, with sides weakly convex, occipital corner round, and posterior margin almost straight; antenna relatively long; scape slender, clearly extending beyond posterolateral corner of head; antennal segment II narrow, 1.6 times as long as segment III; III longer than each of segments IV–XII; clypeus broad, in profile with median portion distinctly convex, in full-face view lateral portion narrow and anterior margin clearly convex; mandible triangular, masticatory margin with a large apical tooth, followed by 9–10 smaller teeth, larger and smaller teeth alternating, but the series as a whole decreasing in size toward basal tooth; basal margin of mandible without denticle; eye slightly convex, located laterally anterior to mid-length of head, relatively large, 0.20 mm in maximum diameter, with eleven ommatidia on longest axis, distance between mandibular base and anterior margin of eye 1.5 times as long as maximum eye length; with head in profile, distance between posterior margin of eye and occipital corner of head 3.4 times as long as distance between mandibular base and anterior margin of eye; frontal lobes relatively close to each other, with roundly convex lateral margins; antennal socket horizontal, in plane of transverse axis of head, and in dorsal view, half concealed by frontal lobe. Mesosoma elongate, in profile with weakly convex dorsal outline; promesonotal suture distinct; metanotal groove absent; mesopleuron not clearly demarcated from mesonotum, but can be separated from metapleuron by a shallow furrow; metapleuron not demarcated from lateral face of propodeum; propodeum with almost straight dorsal outline; propodeal junction rounded; declivity of propodeum shallowly concave; seen from back propodeal declivity tapering above; propodeal spiracle opening elliptical; legs very long.

Petiole cylindrical and sessile, clearly longer than high and broad, its dorsal outline almost straight; with petiole in profile posterodorsal corner with acute angles overhanging declivity of petiole; declivity of petiole shallowly concave; in dorsal view petiole rectangular, its posterior margin concave medially; subpetiolar process weakly developed, subtriangular, located anteroventrally; ventral outline of petiole weakly convex.

Sculpture. Head (including antennal scape), mesosoma, petiole and gaster finely and densely micropunctate; coxae and femora superficially reticulate but shiny. Pubescence white, very short and fine, distributed over whole body and appendages, longer and more oblique on anterior clypeal margin, tip of mandible and hypopygium; setae absent.

Colouration. Dorsum of head dark brown, while lateral face of head reddish brown; mesosoma, petiole and gaster dark brown to reddish brown (tip of gaster yellowish); antenna and legs yellowish brown (funicular segments paler than scape).

Type Material
Holotype. Worker from Southern Thailand, Phatthalung Province, Si Banphot District, Riang Thong Waterfall, Khao Pu Khao Ya National Park, 28.IX.2007, W. Jaitrong leg., Colony no. WJT07-TH-2060 (THNHM-I-02392) deposited in. Paratypes. Three workers, same data as the holotype (THNHM-I-02393 to THNHM-I-02395).

Etymology
The specific name is dedicated to Mr Janya Jareanrattawong of the Royal Forest Department, Thailand who kindly helped W. Jaitrong in ant collecting in southern Thailand.

References based on Global Ant Biodiversity Informatics

 * Phengsi N., W. Jaitrong, J. Ruangsittichai, and S. Khachonpisitsak. 2018. A sibling species of Platythyrea clypeata Forel, 1911 in southeast Asia (Hymenoptera, Formicidae, Ponerinae). ZooKeys 729:87-102.