Myrmecina amamiana

This species is found on the floor of broadleaf forests, nesting in the soil or under stones (Japanese Ant Image Database).

Identification
Terayama (1996) - Resembles Myrmecina graminicola, but easily separated from the latter by the presence of longitudinal rugae on genal areas, prominent eyes, and much stronger longitudinal rugae on head and mesosoma.

Distribution
This species is restricted to Amami-oshima and Tokunoshima of the Amarni Islands, Japan {Terayama, 1996).

Distribution based on Regional Taxon Lists
Palaearctic Region: Japan.

Nomenclature

 *  amamiana. Myrmecina amamiana Terayama, 1996: 29, figs. 66-68 (w.) JAPAN.

Worker
Holotype. HL 0.88 mm; HW 0.93 mm; SL 0.71 mm; CI 106; SL 76; WL 0.98 mm; LP 0.25 mm; PH 0.24 mm; DPW 0.20 mm; TL 3.1 mm.

Head slightly wider than long, with weakly convex sides and concave posterior margin in frontal view. Frons smooth with distinct 14 longitudinal rugae; genae smooth and each with 5 longitudinal rugae. Mandibles with acute apical and subapical teeth and 9 dull, small, and indistinct teeth. Clypeus smooth and shining; anterior margin straight, with a median small lobe and a pair of lateral projection. Antennae with 12 segments; scape 1.3 x head width, not reaching the posterior corner of head; pedicel 1.33 x as long as wide; 3rd to 9th segments each distinctly wider than long; 10th to 12th segments with a ratio from the base, 5:5:11.5 in length. Eyes prominent, each consisting of more than 20 facets; maximum length 0.13 mm, almost the same as length of 10th antennal segment.

Alitrunk with a convex dorsal margin in lateral view; dorsum smooth with 10 strong longitudinal rugae; propodeum with acute small teeth anterolaterally; propodeal spines large, slightly longer than wide, with upturned tip; lateral faces of mesonotum and propodeum smooth with 7-8 longitudinal rugae.

Petiole slightly longer than high in lateral view, in dorsal view 1.1 x as long as wide, with parallel sides. Subpetiolar process present, but low. Postpetiole as long as wide with straight dorsal margin in lateral view; 1.2 x as long as wide in dorsal view; dorsal width 1.1 x dorsal petiole width.

Gaster smooth and subopaque.

Body black; antennal funicles and legs yellowish brown; mandibles, clypeus, and antennal scapes reddish brown.

Variation. The paratype workers vary in head length from 0.83 to 0.90 mm, in head width from 0.93 to 0.95 mm, and in scape length from0.65 to 0.71 mm.

Type Material
Holotype. Worker, Karniya, Amarni-oshima, Kagoshima Pref., '21.III.1984, M. Terayama leg. Paratypes. 12 workers, same data as holotype; 5 workers, Amami-oshima, Kagoshima Pref., 3.VII.1983, M. Terayama leg.; 2 workers, Tokuno-shima, Kagoshima Pref., 20.III.1980, M. Terayama leg.; 6 workers, Hanatoku, Tokuno-shima, Kagoshima Pref., 12.VIII.1986, M. Terayama leg.

References based on Global Ant Biodiversity Informatics

 * Harada Y., M. Enomoto, K. Nishimuta, and H. Mizumata. 2015. Ants of the Amami Islands, central Ryukyus, Japan. Nature of Kagoshima 41: 199–208.
 * 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., S. Kubota, and K. Eguchi. 2014. Encyclopedia of Japanese ants. Asakura Shoten: Tokyo, 278 pp.
 * 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.; Ikudome, S.; Terayama, M. 1999. Identification guide to the Aculeata of the Nansei Islands, Japan. Sapporo: Hokkaido University Press, xii + 831 pp. pp138-317.