Ponera tamon

This species nests in the soil. Larvae spin cocoons within which they pupate. Common in the Nansei Islands, Japan (Japanese Ant Image Database).

Identification
Terayama (1996) - In general appearance similar to Ponera japonica, but easily distinguished from the latter by 1) head much wider and CI 86-91 (77-82 in japonica); 2) petiolar node thiner in dorsal view; 3) posterolateral corners of propodeum only weakly angulate, and 4) posterodorsal border of node not forming an angle.

Leong et al. (2019) - Worker: Ponera tamon can be easily by its short antennal scape not reaching the posterior margin of the head, a clypeus with blunt medial tooth, a metanotal groove distinctly visible, a subtriangular petiolar node when observed in lateral view with a moderately convex posterior margin, and its brown body color.

Distribution based on Regional Taxon Lists
Oriental Region: Taiwan. Palaearctic Region: Japan.

Nomenclature

 *  tamon. Ponera tamon Terayama, 1996: 11, figs. 10-16 (w.q.) JAPAN.

Worker
Holotype. HL 0.51 mm; HW 0.45 mm; SL 0.38 mm; 0 88; SI 84; WL 0.74 mm; PW 0.35 mm; PH 0.35 mm; PNL 0.18 mm; DPW 0.28 mm; PNI 80; TL 2.5 mm.

Head 1.17 x as long as wide, with slightly convex sides and slightly concave posterior margin in frontal view. Eyes small, each consisting of 3-4 indistinct facets. Antennae with 12 segments; scape short, not reaching the posterolateral margin of head; apical 5 segments forming a club.

Profile of alitrunk as in figure; dorsal margin almost straight; posterolateral comers of propodeum dully angulated. Petiolar node thick and wide, with straight anterior margin and convex posterior margin in lateral view; posterodorsal comer rounded, not forming an angle; viewed from above, node 0.45 x as long as wide, with very slightly concave posterior margin. Subpetiolar process with acute posterolateral teeth; fenestra circular.

First gastral tergite 0. 83 x as long as wide in dorsal view; 2nd tergite 0.62x as long as wide.

Head and alitrunk coarsely microreticulate; punctures separated by less than 0.5 x their own diameters. Gaster moderately punctate; punctures on 1st tergite less than those on 2nd.

Pubescence moderately abundant, and erect hairs present on the dorsa of alitrunk and petiole, and entire gaster.

Body black; clypeus reddish brown; mandibles, antennae and legs yellowish brown.

Variation. Dorsal width of petiole in workers varies in the materials of Okinawa and Amami Is. from 0.28 to 0.32 mm, and in that of Taiwan from 0.31 to 0.39 mm. Coloration of body also varies from dark brown to almost black. These differences may reflect the geographical variation within a single species. Morphometric data are summarized in Table 1.

Leong et al. (2019) - (n=22): HL 0.51–0.59; HW 0.44–0.52; SL 0.32–0.41; A06L 0.02; A07L 0.03; A08L 0.04; A09L 0.06; A10L 0.07; PrW 0.33–0.40; WL 0.66–0.84; PeH 0.30–0.42; PeNL 0.16–0.21; PeW 0.26–0.33; ATL 0.37–0.45; ATW 0.41–0.52; CI 83–91, SI 71–86, PeI 74–87, LPeI 46–55, DPeI 152–184, ATI 76–93.

Head. In full-face view, head structure subrectangular and slightly longer than broad (CI: 84–91), with slightly convex posterior margin, moderately convex lateral margins and broadly rounded posterolateral corners. Eye small; composed of a total of 4 to 5 indistinct facets. Anterior clypeal margin with 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, with a remaining distance of about 5% of the scape length to the posterolateral corner; average ratio of the length of antennomeres 7/6:8/6:9/6:10/6 = 1.17: 1.89: 2.41: 3.08 (n=22).

Mesosoma. Mesosomal dorsum in lateral view convex. Pronotum in dorsal view with acutely convex anterior margin, and convex lateral margins. Metanotal groove distinctly incised with fine suture. Lateral mesopleural suture weakly incised. Propodeal dorsum in dorsal view broad, with straight lateral margins. Propodeal corner in lateral view rounded; propodeal dorsum and declivity forming approximatively a 115 degree angle.

Metasoma. Petiolar node in dorsal view arched and moderately thin, with broadly convex anterior margin, and slightly convex posterior margin. Petiolar node in lateral view subtriangular and moderately thick, with straight anterior margin, and moderately convex posterior margin; with distinct projection on posterodorsal corner, dorsum forming a blunt angle. Subpetiolar process with small and circular fenestra, anteroventral corner blunt, concave ventral margin with small teeth. Third abdominal tergum generally broader than long (ATI: 76–93), with slightly convex anterior margin, almost straight lateral margins.

Sculpture. Head densely punctate. Mandible sparsely punctate. Mesosoma evenly punctate. Mesopleuron with weakly striate lower portion and sparsely punctate upper portion. Metapleuron with weakly striate lower portion and smooth upper portion. Propodeal declivity smooth and shining. Lateral face of petiole evenly punctate, posterior face smooth, dorsum with few punctures. The third and fourth abdominal segments evenly punctate, other segments with few punctures.

Pubescence. Head, antennae, mesosoma, petiole, and gaster with evenly distributed short hairs. Mesopleuron, metapleuron, propodeum and lateral face of petiole with few short hairs, and with glabrous upper portion of mesopleuron. Dorsal and ventral faces of head, anterior margin of clypeus, sides of mandibles, dorsum of petiolar node, gastral sterna and posterior half of gastral terga with many long erect hairs. Subpetiolar process with a few long erect hairs.

Color. Body color brown. Mandible, clypeus, antennae, legs, and apex of metasoma lighter.

Queen
Paratypes. HL 0.60-0.63 mm; HW 0.53-0.55 mm; SL0.45-0.46 mm; CI 87-88; SI 86-88; WL 0.90-0.92 mm; PW 0.48-0.53 mm; PNL 0.18-0.20 mm; PH 0.43-0.45 mm; DPW 0.35-0.38 mm; TL 3.0-3.2 = (n = 3).

Head slightly longer than wide. Antennal scapes almost reaching the posterolateral comers of head in frontal view. Eyes 0.13-0.14 mm in length. Ocelli forming an acute triangle.

Alitrunk and petiole as in Figures. Petiolar node with straight anterior margin and convex posterolateral corner in lateral view; disc thin, 0.32x as long as wide, with straight posterior margin in dorsal view.

Head and alitrunk coarsely microreticulate; punctures separated by less than 0.5 x their own diameters. Gaster moderately punctate. Color as in worker.

Leong et al. (2019) - (n=3): HL 0.59–0.61; HW 0.52–0.55; SL 0.40–0.45; A06L 0.03; A07L 0.03; A08L 0.05; A09L 0.06; A10L 0.08; PrW 0.44–0.50; WL 0.88–1.11; PeH 0.33–0.47; PeNL 0.19–0.21; PeW 0.27–0.39; ATL 0.40–0.54; ATW 0.46–0.65; CI 89–92, SI 77–81, PeI 65–80, LPeI 45–57, DPeI 150–185, ATI 84–90.

Head: Similar to worker caste, but with large and oval Eye, maximum diameter of each eye about 0.13 mm with 10 ommatidia along the maximum diameter. Three ocelli present, and forming an equilateral triangle. Antennal scape similar to worker; average ratio of the length of antennomeres 7/6:8/6:9/6:10/6 = 1.22: 1.74: 2.16: 2.75 (n=3).

Mesosoma. Mesosomal dorsum in lateral view broadly convex. Pronotum in dorsal view with convex anterior margin, and broadly convex lateral margins. Scutum subtrapezoidal, narrow posteriad, with broadly convex anterior margin, and concave posterior margin. Transcutal suture distinct and broad. Scutellum subrectangular. Anapleural sulcus clearly incised. Propodeal-metapleural suture indistinct. Propodeal dorsum in dorsal view broad, with straight lateral margins. Propodeal corner rounded and almost forming approximatively 115 degree angle.

Metasoma. Petiolar node in dorsal view oval and moderately thin, broader than long, with broadly convex anterior margin, and slightly convex posterior margin. Petiolar node in lateral view subconical and moderately thick, moderately convex anterior and posterior margins, dorsum well convex. Subpetiolar process with small and circular fenestra, anteroventral corner blunt, concave ventral margin, and posteroventral corner concave with a pair of small teeth. The third abdominal segment similar to worker caste (ATI: 105).

Sculpture, Pubescence, and Color: Similar to worker caste.

Type Material
Holotype. Worker, Uken-son, Amami-oshima, Kagoshima Pref., Japan, 1.VII.1983, M. Terayarna leg.

Paratypes. Japan: - 7 workers, 1 female, same data as holotype; 13 workers, Sumiyo-son, Amami-oshima, Kagoshima Pref., M. Terayarna leg.; 1 worker, Nazeshi, Amami-oshima, Kagoshima Pref., 21.III.1980, M. Terayama leg.; 9 workers, 1 female, Okinoerabu-jima, Kagoshima Pref., 17.III.1989, M. Terayama leg., 1 worker, Yoron-jima, Kagoshima Pref., 14.III.1980, M. Terayama leg.; 3 workers, 1 female, Hirara, Miyako-jima, Okinawa Pref., 20.VIII.1979, M. Terayama leg.; 2 workers, Sonai, Iriomote-jima, Okinawa Pref., 29.VII.1979, M. Terayama leg.; 29 workers, Izena-jima, Okinawa Pref., 31.III.1985, H. Takamine leg.; 16 workers, Nago, Okinawa-jima, Okinawa Pref., 3.X.1984, H. Takamine leg.; 33 workers, Naha, Okinawa-jima., Okinawa Pref., 15.XII.1984, H. Takamine leg.; 6 workers, 2 females, Sata-misaki, Kagoshima Pref., 9.VIII.1984, S. Kubota leg.

Leong et al. (2019): Type material examined: JAPAN. Paratypes, 2 workers, Okinoerabu-jima, Kagoshima Pref., 17 III 1989, M Terayama leg. 1 worker, Sonai, Iriomote-jima, Okinawa Pref., 31 III 1985, M Terayama leg (: LCM_MT-Ponera-25). 1 dealate queen and 2 workers, Uken-son, Amami-oshima, Kagoshima Pref., 1 VII 1983, M Terayama leg (: LCM_MT-Ponera-26, LCM_MT-Ponera-28). 3 workers, Nago, Okinawai Is., 3 X 1984, M Terayama leg (: LCM_MT-Ponera-27). 9 workers, Sumiyo-son, Amami-oshima, Kagoshima Pref., VII 1983, M Terayama (: LCM_MT-Ponera-29, LCM_MT-Ponera-30, LCM_MT-Ponera-31, LCM_MT-Ponera-32).

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

References based on Global Ant Biodiversity Informatics

 * Fukumoto S., Jaitrong W. and Yamane S.K. 2013. Ant Fauna of Kuro-shima, Iwo-jima and Take-shima islands, Kagoshima Prefecture, southwestern Japan. Nature of Kagoshima 39: 119-125
 * Fukumoto S., R. Satria, T. Maeda, and S. Yamane. 2014. Ant fauna of Gaja-jima, Tokara Islands, southwestern Japan. Nature of Kagoshima 40: 127131.
 * Fukumoto S., W. Jaitrong, and S. Yamane. 2013. Ant fauna of Take-shima, Iwo-jima and Kuro-shima islands, Kagoshima Prefecture, southwestern Japan. Nature of Kagoshima 39: 99-105.
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Harada Y., M. Enomoto, K. Nishimuta, and H. Mizumata. 2015. Ants of the Amami Islands, central Ryukyus, Japan. Nature of Kagoshima 41: 199–208.
 * Harada Y., M. Enomoto, N. Nishimata, and K. Nishimuta. 2014. Ants of the Tokara Islands, northern Ryukyus, Japan. Nature of Kagoshima 40: 111121.
 * Hosoichi S., M. Yoshimura, Y. Kuboki, and K. Ogata. 2007. Ants from Yakushima Island, Kagoshima Prefecture. Ari 30: 47-54.
 * Hosoishi S., M. Yoshimura, Y. Kuboki, and K. Ogata. 2007. Ants from Yakushima Island, Kagoshima Prefecture. Ari 30: 47-54.
 * Katayama M., T. Hosoya, and W. Toki. 2013: First survey of ground-dwelling ants (Hymenoptera: Formicidae) on the uninhabitedGaja-jima Island, theRyukyu archipelago, Japan.Entomol. Fennica 24: 216222.
 * Leong C. M., B. Guénard, S. F. Shiao, & C. C. Lin. 2019. Taxonomic revision of the genus Ponera Latreille, 1804 (Hymenoptera: Formicidae) of Taiwan and Japan, with a key to East Asian species. Zootaxa 4594: 1-86.
 * Shimono A., and S. Yamane. 2003. Ant species diversity on Okinoerabu-jima, the Ryukyus, southern Japan. For the Establishment of Remote Islands Study (Kagoshima Univ.) 3: 11-29.
 * Terayama M. 1996. Taxonomic studies on the Japanese Formicidae, part 2. Seven genera of Ponerinae, Cerapachyinae and Myrmicinae. Nature & Human Activities 1: 9-32.
 * Terayama M. 2009. A synopsis of the family Formicidae of Taiwan (Insecta: Hymenoptera). Research Bulletin of Kanto Gakuen University. Liberal Arts 17:81-266.
 * Terayama M., S. Kubota, and K. Eguchi. 2014. Encyclopedia of Japanese ants. Asakura Shoten: Tokyo, 278 pp.
 * Terayama Mamoru. 2009. A synopsis of the family Formicidae of Taiwan (Insecta, Hymenoptera). The Research Bulletin of Kanto Gakuen University 17: 81-266.
 * Terayama, M. 2009. A synopsis of the family Formicidae of Taiwan (Insecta; Hymenoptera). The Research Bulletin of Kanto Gakuen University 17: 81-266.
 * Yamane S. 2016. How many species of Ants in Amami Islands? (in Japanese). Part 2, chapter 1 in How many species of Ants in Amami Islands? Pp. 92-132.
 * Yamane S., S. Ikudome, and M. Terayama. 1999. Identification guide to the Aculeata of the Nansei Islands, Japan. Sapporo: Hokkaido University Press, xii + 831 pp. pp, 138-317.
 * Yamane S., Y. Harada, and K. Eguchi. 2013. Classification and ecology of ants. Natural history of ants in Southern Kyushu. 200 pages
 * Yamane S., and S. Ikudome. 2008. Ants, wasps and bees of Kuro-shima Northern Ryukyus, Japan (Hymenoptera, Aculeata). Bull. Inst. Minami-Kyushu Reg. Sci. (Kagoshima Women's Jr. Coll.) 24: 1-9.
 * Yamane S.; Ikudome, S.; Terayama, M. 1999. Identification guide to the Aculeata of the Nansei Islands, Japan. Sapporo: Hokkaido University Press, xii + 831 pp. pp138-317.