Ponera kohmoku

This species inhabits the floor of the broad-leaved forest, and nests in the soil. Alate queens have been collected in the middle August on Yaku Island, Japan. Rather rare. (Japanese Ant Image Database)

Identification
Terayama (1996), Leong et al. (2019) - The large eyes of workers, consisting of around 20 facets, distinguish this species from its congeners.

Distribution based on Regional Taxon Lists
Palaearctic Region: Japan.

Nomenclature

 *  kohmoku. Ponera kohmoku Terayama, 1996: 9, figs. 1-6 (w.q.) JAPAN.

Taxonomic Notes
Leong et al. (2019): A specimen collected from KiuShiu, Shiroyama, Japan, is mistakenly labeled as a type of Ponera scabra at (AntWeb images, specimen CASENT0915299). Ponera scabra was described from Mt. Maya, Hyogo Prefecture, Japan. Santschi (1937: 364) identified the KiuShiu specimen as a gynecoid worker of P. scabra. However, this specimen can be easily identified as P. kohmoku Terayama, 1996 by the combination of the following characters: large compound eye (ca. 30 facets), distinct metanotal groove and subcircular petiolar node in dorsal view; in contrast to P. scabra, which has small compound eye (ca. 5 facets), an indistinct metanotal groove and an arched petiolar node in dorsal view. Thus, there are no records of gynecoid workers in Ponera after the exclusion of Santschi’s record.

Worker
Holotype. HL 0.80 mm; HW 0.68 mm; SL 0.65 mm; CI 84; SI 96; WL 1.25 mm; PW 0.58 mm; PNL 0.35 mm; PH 0.63 mm; DPW 0.45 mm; PNI 78; TL 3.6 mm.

Head subrectangular, with slightly convex sides and almost straight posterior margin in frontal view. Mandibles with 3 developed apical teeth followed by a series of about 10 minute denticles. Clypeus with a blunt but distinct median tooth. Eyes large for this genus, slightly convex, and each consisting of about 25 indistinct facets; maximum diameter 0.10 mm. Antennae with 12 segments; scape relatively long, slightly exceeding median posterior margin of head in frontal view; club not differentiated; 8th to 12th segments in a ratio of about 7:7:9:11:18 in length; terminal segment 1.4 x as long as wide.

General shape of alitrunk and petiole as in Fig. 5; lateral promesonotal and dorsal mesonotal-propodeal sutures distinctly incised; posterolateral corner of propodeum dully angulate. Petiolar node wider than long in dorsal view, with broadly convex anterior margin and straight posterior margin. Subpetiolar process with a pair of strong posterolateral teeth; fenestra relatively rarge and oval.

Head and antennal scapes microreticulate; mandibles smooth and shining. Dorsum of alitrunk and petiole microreticulate and closely punctate; mesepisterna and lateral faces of propodeum shining and weakly punctate; declivitous face of propodeum smooth and shining. Gaster closely punctate; punctures on 2nd gastral tergite weaker than those on the 1st. Pubescence moderately abundant; erect or suberect hairs present on mandibles, antennal scapes, dorsa of alitrunk and petiolar node, and entire gaster.

Body black with brownish tinge; clypeus and subpetiolar process brown; mandibles, antennae, legs and tip of gaster reddish brown.

Variation. Ten paratype workers with the following measurements and indices: HL 0.83-0.89 mm; HW 0.70-0.75 mm; SL0.63-0.66 mm; CI 85-88; SI 97-91; WL 1.20-1.28 mm; PW 0.58-0.61 mm; PNL 0.34-0.35 mm; PH 0.63-0.68 mm; DPW 0.43-0.48 mm; PNI 71-78; TL 3.4-3.7 mm.

Eyes consisting of 22 to 30 indistinct facets.

Leong et al. (2019) - (n=6): HL 0.83–0.89; HW 0.70–0.77; SL 0.61–0.68; A06L 0.05; A07L 0.05; A08L 0.08; A09L 0.10; A10L 0.11; PrW 0.57–0.65; WL 1.06–1.29; PeH 0.62–0.65; PeNL 0.34–0.37; PeW 0.44–0.51; ATL 0.63–0.71; ATW 0.76–0.80; CI 80–87, SI 82–91, PeI 73–82, LPeI 54–58, DPeI 124–143, ATI 81–89.

Head. In full-face view, head subrectangular and distinctly longer than broad (CI: 80–87), with straight posterior margin, moderately convex lateral margins, and bluntly rounded posterolateral corners. Eye large; composed of a total of 18–22 indistinct facets. Anterior clypeal margin with strong and blunt medial tooth. Masticatory margin of mandible with a series of about ten indistinct denticles, and three large teeth on the apical part. Antennal scape, when laid backward, exactly reaching the posterolateral corner; average ratio of the length of antennomeres 7/6:8/6:9/6:10/6 = 1.16: 1.68: 1.98: 2.24 (n=6).

Mesosoma. Mesosomal dorsum in lateral view slightly convex. Pronotum in dorsal view with broadly convex anterior margin, and moderately convex lateral margins. Metanotal groove deeply and broadly incised. Lateral mesopleural suture clearly incised. Propodeal dorsum in dorsal view narrow, with straight lateral margins. Propodeal corner in lateral view angular; propodeal dorsum and declivity forming approximatively a 130 degree angle.

Metasoma. Petiolar node in dorsal view subcircular and thick, with well convex anterior margin, and moderately convex posterior margin. Petiolar node in dorsal view well thick and subtrapezoid, with straight anterior and posterior margins, and slightly convex dorsal margin. Subpetiolar process thick with medium-sized and oval fenestra, anteroventral corner blunt, straight ventral margin, and posteroventral corner concave with a pair of medium-sized teeth. Third abdominal tergum broader than long (ATI: 81–89) and narrow anteriad, with broadly convex anterior margin, and well convex lateral margins.

Sculpture. Head densely punctate. Mandible sparsely punctate. Mesosomal dorsum in dorsal view evenly punctate. Mesopleuron, metapleuron and propodeum evenly striate. Propodeal declivity smooth and shining. Lateral face of petiole evenly punctate, posterior face smooth, dorsum rough and evenly punctate. The third and fourth abdominal segments densely punctate, other segments smooth and shining with few punctures.

Pubescence. Head, antennae, mesosoma, petiole, and gaster with evenly distributed short hairs. Mesopleuron, metapleuron, propodeum and lateral face of petiole with scattered short hairs. Dorsal and ventral faces of head, anterior margin of clypeus, sides of mandibles, dorsum of petiolar node and gaster with many long erect hairs. Subpetiolar process with a few long erect hairs.

Color. Body color dark. Mandible, clypeus, antennae, legs, and apex of gaster orange.

Queen
Paratypes. HL 0.93-0.95 mm; HW 0.78-0.80 mm; SL0.70-0.71 mm; CI 84-85; SI 89-90; WL 1.55-1.18 mm; AW 0.75-0.67 mm; PNL 0.38-0.39 mm; PH 0.68-0.70 mm; DPW 0.51-0.53 mm; PNI 74-75; TL4.0-4.3 mm (n = 4).

Head and alitrunk as inFigs. Eyes large, 4.0-4.3 mm in diameter. Ocelli small, forming an acute triangle. Antennal scapes exceeding posterior margin of head. Petiolar node converging above in lateral view; disc 0.53 x as long as wide, with weakly concave posterior margin in dorsal view. Color as in worker.

Leong et al. (2019) - (n=1): HL 0.94; HW 0.81; SL 0.71; A06L 0.06; A07L 0.06; A08L 0.09; A09L 0.11; A10L 0.11; PrW 0.75; WL 1.52; PeH 0.74; PeNL 0.37; PeW 0.55; ATL 0.80; ATW 0.90; CI 86, SI 88, PeI 74, LPeI 50, DPeI 150, ATI 88.

Head. Similar to worker caste, but with large and oval Eye, maximum diameter of each eye about 0.21 mm with 15 ommatidia along the maximum diameter. Three ocelli present, and forming a subequilateral triangle. In full-face view, scape similar to worker; average ratio of the length of antennomeres 7/6:8/6:9/6:10/6 = 1.07: 1.53: 1.80: 1.85 (n=1).

Mesosomal dorsum in lateral view broadly convex. Pronotum in dorsal view with convex anterior margin, and broadly convex lateral margins. Scutum suboval and narrow posteriad, with moderately convex anterior margin, and slightly convex posterior margin. Transcutal suture distinct and broad. Scutellum suboval. Anapleural sulcus clearly incised. Propodeal-metapleural suture weakly incised. Propodeal dorsum in dorsal view broad, with straight lateral margins. Propodeal corner rounded; propodeal dorsum and declivity forming approximatively a 120 degree angle.

Metasoma. Petiolar node in dorsal view thick and arched, broader than long, with broadly convex anterior margin, and slightly convex posterior margin. Petiolar node in lateral view subrectangular and moderately thick, with straight anterior and posterior margins. Subpetiolar process with large and oval fenestra, anteroventral corner blunt, ventral margin straight, and posteroventral corner concave with a pair of small teeth. The third abdominal segment similar to worker caste (ATI: 88).

Sculpture. Similar to worker caste.

Pubescence. Similar to worker caste.

Color. Similar to worker caste.

Type Material
Holotype. Worker, Kurio, Yaku-shima, Kagoshima Pref., 23.III.l981, M. Terayama leg.

Paratypes. 23 workers, 1 female, same data as holotype; 2 females, Kusukawa, Yaku-shima, Kagoshima Pref., 22.III.1981, M. Terayama leg.; 2 workers, Yaku-shima, Kagoshima Pref., 16.X.1984, M. Terayarna leg.; 4 workers, Anbou, Yaku-shima, Kagoshima Pref., M. Terayarna leg.; 3 workers, 20.VIII.1983, Shiroyarna, Kagoshima-shi, Kagoshima Pref., 20.VIII.1983, S. Kubota leg.; 2 workers, same locality, 21.VIII.1983, S. Kubota leg.; 1 worker, Sata-misaki, Kagoshima Pref., 10.VIII.1984, M. Terayarna leg.; 1 female, Yaku-shima, Osumi Is., Kagoshima Pref., 19.VIII.1983, Sk. Yamane leg.; 28 workers, Shimonoseki, Fukuoka Pref., 6.IV.1993, O. Kitade leg.

Leong et al. (2019): Type material examined: JAPAN. Paratypes, 6 workers and 1 dealate queen, Kurio, Yaku-shima, Kagoshima Pref., 23 III 1981, M Terayama leg (: LCM_MT-Ponera-13, LCM_MT-Ponera-14, LCM_MT-Ponera-15). 1 worker, Sata-Misaki, Kagoshima Pref., 10 III 1981, M Terayama leg (LCM_MT-Ponera-16).

Etymology
The specific name is the Japanese noun Kohmoku-ten, which is the name of one of the four guardian deities in buddhism.

References based on Global Ant Biodiversity Informatics

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