Vollenhovia amamiana

This species nests in the rotten wood in forests.

Identification
Terayama & Kinomura (1997) - This species closely resembles Vollenhovia emeryi, in having the larger size (HL > 0.55 mm, HW > 0.50 mm), presence of a large brown spot of frons, and a developed subpetiolar process. It is distinguished from the latter by the absence of propodeal spines, and having an angulate posterodorsal comer of petiolar node in profile.

Distribution based on Regional Taxon Lists
Palaearctic Region: Japan.

Nomenclature

 *  amamiana. Vollenhovia amamiana Terayama & Kinomura, 1997: 3, figs. 1, 3, 7 (w.q.) JAPAN.

Worker
Holotype. Worker. HL 0.65 mm; HW 0.60 mm; SL 0.40 mm; CI 92; SI 67; WL 0.83 mm; PL 0.30 m; PH 0.33 mm; DPW 0.18 mm; TL 2.7 mm.

Head slightly longer than wide, with subparallel sides and concave posterior margin in frontal view. Mandibles with 7 teeth, basalmost tooth distinct. Clypeal carinae diverging toward the anterior end. Antennae with 12 segments; scape 0.61 x head length. Eyes 0.14 mm in diameter.

Dorsal outline of promesonotum almost straight in profile; metanotal groove very weakly incised dorsally; dorsal outline of propodeum straight; posterodorsal corner of propodeum dully angulate, not forming distinct tooth.

Petiole higher than long, with flat dorsal outline in profile; anterodorsal and posterodorsal margins weakly angulate. Subpetiolar process developed, with relatively strongly convex ventral margin; its thin lamellar wall 0. 08 mm in height. Postpetiole slightly longer than high, highest at midlength, with broadly convex dorsal outline in profile; posterodorsal margin convex except the posterior collar.

Head and dorsum of alitrunk shagreened with large coarse punctures: punctures separated less than 0. 5 x their own diameters; promesonotal dorsum without unsculptured longitudinal band medially; mesopleura and lateral surfaces of propodeum coarsely punctated. Petiole and postpetiole reticulate; sculpture of postpetiole weaker than that of petiole. Gaster smooth and subopaque except the anterior half of 1st tergite scattered with very small punctures.

Color: reddish brown; mandibles, antennae, and legs yellowish brown; frons with a large brown spot.

Queen
Paratype. HL 0.68 mm; HW 0.65 mm; SL 0.43 mm; CI 96; SI 65; WL 1.08 mm; PL 0.30 mm; PH 0.35 mm; DPW 0.20 mm; TL 3.0 mm (one measured).

Head slightly longer than wide, with shallow concave posterior margin; eyes 0.15 mm in diameter; ocelli forming obtuse triangle.

Alitrunk 0.58 mm in maximum dorsal width; dorsum of pro- and mesonotum shagreened with coarse punctures; unsculptured longitudinal band absent on dorsum of mesonotum; posterodorsal corner of propodeum dully angulate. not forming distinct tooth in profile.

Petiole higher than long, with angulate anterodorsal and posterodorsal corners in profile. Subpetiolar process large and high, with relatively strongly convex ventral margin. Postpetiole highest at midlength, with convex dorsal outline in profile.

Color: reddish brown; ocellar triangular area blackish brown; frons with a large brown spot.

Variation. Five para type workers with the following measurements and indices: HL 0.58-0.64 mm; HW 0.55-0.59 mm; SL 0.38-0.40 mm; CI 88-92; SL 68-71; WL 0.80-0.83 mm; PL 0.28-0.30 mm; PH 0.31-0.33; DPW 0.18-0.20 mm; TL 2.6-2.7 mm.

Eye diameter varies from 0.12 to 0.13 mm.

Type Material
Holotype. Worker, Tatsuno-gou. Amamioshima, Kagoshima Pref., 25.XI.1994, K. Yamauchi leg. Paratypes. 1 female, 23 workers, same data as holotype; 1 female, 4 workers, Kinsakubara, Amamioshima, Kagoshima Pref., 6.VIII.1984, M. Morisita leg.; 1 worker, Tokuno-shima, Kagoshima Pref., 6.VIII.1984, M. Terayama leg.

The holotype and some paratypes are deposited in the Museum of Nature and Human Activities. Hyogo, and the other paratypes are in the National Institute of Agro-Environmental Sciences, Tsukuba, and National Science Museum, Tokyo.

Etymology
The specific epithet refers to the type locality.

Determination Clarifications
This species corresponds to Vollenhovia sp. 3 ("Oh-umematsuari" in Japanese) in Terayama and Yamauchi (1992).

References based on Global Ant Biodiversity Informatics

 * 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.