Myrmecina raviwonghei

The type series was collected from small rotting wood in lowland dry evergreen forest. A colony from Kanchanaburi Province, western Thailand was collected from leaf litter in a dry evergreen forest. Several specimens from Thung Yai Naresuan East Wildlife Sanctuary, Tak Province were collected in highland (900–1000 m a.s.l.) primary forests. Thus, this species inhabits primary evergreen forest from lowland to highland. (Jaitrong et al., 2019)

In China, this species is only known from Xishuangbanna in Yunnan Province. One worker was collected within limestone rainforest in the Xishuangbanna Tropical Botanical Garden, situated at an elevation of 640 m. Another worker was collected from a leaf litter extraction in a rainforest near Man Sai village at 675 m. Two additional workers were collected from leaf litter in a rubber plantation at 620 m. (Liu et al., 2022)

Identification
Jaitrong et al. (2019) - This species is easily distinguished from the other members of the genus by the dorsum of head and mesosoma punctured with longitudinal rugae, the fine and dense punctures covering the first gastral tergite, and the strongly concave anterior margin of the first gastral tergite.

Okido, Ogata, and Hosoishi (2020) - A member of the  Myrmecina gracilis complex. Among these species, M. raviwonghei is distinguished by a broad head and sculptured first gastral sternum without a ridge along its anterior median portion.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand.

Biology
Okido, Ogata, and Hosoishi (2020) - Ergatogynes are present in this species.

Nomenclature

 *  raviwonghei. Myrmecina raviwonghei Jaitrong, Samung, Waengsothorn & Okido, 2019: 3, figs. 1-5 (w.) THAILAND.

Worker
Holotype: HL 0.61; HW 0.59; MDL 0.30; EL 0.13; SL 0.46; WL 0.73; PNW 0.46; PSL 0.17; PTH 0.20; PTL 0.20; CI 97; MDI 49; SI 78; PTHI 100. Paratypes (n = 10): HL 0.59–0.63; HW 0.56–0.63; MDL 0.23–0.30; EL 0.08–0.13; SL 0.40–0.46; WL 0.66–0.76; PNW 0.40–0.46; PSL 0.17–0.20; PTH 0.18–0.20; PTL 0.20; CI 100; MDI 41–50; SI 71–78; PTHI 92–100.

Coloration. Body black, tip of gaster reddish brown; mandible, antenna and legs yellowish brown; forecoxa dark brown. Structure. Head in full-face view, subrectangular, almost as long as broad; posterior margin weakly concave medially; posterolateral corner rounded, not projected posteriorly; lateral margin weakly convex. Mandible broad, subtriangular; masticatory margin bent at mid-length, apical tooth large followed by medium size subapical tooth, 5 small teeth and medium size basal tooth. Dorsal face of clypeus shallowly concave; median portion of anterior clypeal margin projected, usually with three processes. Frontal carina virtually absent, indistinguishable from rugae of head. Eye small, with 4–6 ommatidia, maximum diameter of eye 0.08–0.13 mm. Antenna 12- segmented, with 3-segmented club; scape short, not reaching posterolateral corner of head; segment II almost as long as broad and broader than each of segments III– VIII; terminal segment (XII) as long as III–VIII combined.

Dorsal outline of mesosoma in profile, weakly convex. Pronotum without denticles on its dorsum; anterior ventrolateral portion of pronotum forming distinct process, directed forward and downward; mesonotum completely fused with pronotum; mesopleuron not differentiated from metapleuron. Propodeum in dorsal view not demarcated anteriorly; anterior pair of denticles present on propodeal dorsum, very small and short (difficult to distinguish them from longitudinal rugae on propodeum); propodeal spine relatively long, almost as long as or slightly longer than broad at base; propodeal declivity, seen from back, tapering above and shallowly concave. Petiole short, in dorsal view slightly longer than broad, rectangular; in profile view, as long as broad, its anterior slope almost straight, and dorsal face almost straight; ventral outline straight with a small anterior denticle; postpetiole in dorsal view broader than petiole and slightly shorter than broad; sternopostpetiolar process distinctly projected with acute anterior apex. Gaster in dorsal view slightly elongate circular; anterior margin of first gastral tergite strongly concave.

Sculpture. Dorsum of head punctured with longitudinal rugae; ventrolateral area (temple + gena) of head with rugae; ventral face with irregular rugae; mandible largely smooth and shiny, with striation at base; clypeus somewhat smooth and shiny; antennal scape punctate. Mesosoma entirely punctured with longitudinal rugae; coxae smooth and shiny, forefemur superficially reticulate with smooth and shiny interspaces; mesofemur and metafemur smooth and shiny. Petiole punctured with few distinct rugae. First gastral tergite finely punctate; first gastral sternite reticulate.

Pilosity. Body covered with abundant short erect hairs, hairs on first gastral tergite slightly longer than those on head and mesosoma; clypeus with several erect hairs, and pair of long hairs arising from median tooth of its anterior margin; scape with many suberect to erect hairs that are longer than scape width; all legs with numerous suberect to erect hairs.

Type Material
Holotype – worker (THNHM-I-05470, ), NE Thailand: Nakhon Ratchasima Province, Wang Nam Kheao District, Udom Sub Subdistrict, 14.46805ºN, 101.90416ºE, 22.VI 2018, W. Jaitrong leg., WJT220618- 6. Paratypes: 24 workers (THNHM-I-05471,, , THNHM, ), same data as holotype

Etymology
The specific name is dedicated to Dr. Rawin Raviwonghe, the president of the National Science Museum, Thailand, who kindly supported us in field surveys.

References based on Global Ant Biodiversity Informatics

 * Jaitrong W., Y. Samung, S. Waengsothorn, and H. Okido. 2019. A new species of the ant genus Myrmecina Curtis, 1829 (Hymenoptera: Formicidae, Myrmicinae) from Thailand. Far Eastern Entomologist 383: 1-7.