Vollenhovia benzai

This species is polygynous. It nests in decaying wood or in the soil in forests. Wingless ergatoid females are known from the Amami-oshima Island population, in which normal winged females are also present. Further studies are needed to clarify their possible taxonomic implications and biological significance. 

Identification
Terayama & Kinomura (1997) - Among the 4 described species is distinguishable as follows: differs V. benzai from Vollenhovia emeryi of Japan and Vollenhovia pyrrhoria of China by having a low and small subpetiolar process, dully angulate posterodorsal corner of propodeum, lacking large brown spot on frons, and smaller body size (HL 0.50-0.53 mm and HW 0.43-0.48 mm in benzai workers; HL 0.55-0.59 mm and HW 0.50-0.54 mm in emeryi workers (n = 10), and HL 0.60 mm and HW 0.55 mm in pyrrhoria worker (one paratype is measured): V. benzai differs from Vollenhovia satoi, from Taiwan by having less incised metanotal groove (deeply incised dorsally in satoi); and V. benzai differs from Vollenhovia nipponica, which is a workerless social parasitic species by having a low and small subpetiolar process and a dully angulate posterodorsal corner of the propodeum in female. It is also distinguished from the other Japanese congeners in workers by the following characteristics: 1) frons without large brown spot; 2) dorsum of promesonotum coarsely punctate, without unsculptured longitudinal band medially; 3) propodeal teeth absent; 4) subpetiolar process low, longer than high; 5) postpetiole highest at midlength in profile.

Distribution based on Regional Taxon Lists
Palaearctic Region: Japan.

Nomenclature

 *  benzai. Vollenhovia benzai Terayama & Kinomura, 1997: 2, figs. 2, 6 (w.q.) JAPAN.

Worker
Holotype. Worker. HL 0.53 mm; HW 0.48 mm; SL 0.29 mm; CI 90; SI 60; WL 0.60 mm; PL 0.23 mm; PH 0.21 mm: DPW 0.14 mm: TL 2.0 mm.

Head slightly longer than wide, with subparallel sides and weakly concave posterior margin in frontal view. Mandibles with 7 teeth; basalmost tooth minute. Clypeal carinae subparallel. Antennae with 12 segments; scape 0.55 x head length. Eyes 0.13 mm in diameter.

Dorsum of promesonotum straight in profile: metanotal groove not incised dorsally; posterodorsal corner of propodeum dully angulated, without a dorsal tooth in profile.

Petiole higher than long, with convex dorsal outline in profile; anterodorsal corner rounded, not forming distinct angle. Subpetiolar process low and small; its thin lamellar wall ca. 0.12 mm in height. Postpetiole as long as high and highest at midlength, with convex dorsal outline in profile; posterodorsal margin convex.

Head shagreened with large coarse punctures; space between punctures less than 0.5 x their own diameters; dorsum of alitrunk coarsely punctated with numerous longitudinal ruglae and without unsculptured longitudinal band medially; mesopleura. Propodeum and petiole reticulate; sculpture on petiole weaker than that on propodeum; postpetiole smooth in most part gaster and legs smooth and subopaque.

Color: reddish brown; mandibles, antennae, and legs yellowish brown; frons without dark brown spot.

Queen
Paratype. HL 0.53 mm: HW 0.50 mm; SL 0.35 mm: CI 95; SI 70; WL 0.78 mm: PL 0.25 mm; PH 0.24 mm; DPW 0.35 mm; TL 2.5 mm (one measured).

Head slightly longer than wide. with weakly concave posterior margin in frontal view; eyes 0.13 mm in diameter; ocelli small. forming a right angled triangle.

Alitrunk 0.48 mm in maximum dorsal width; dorsum of metanotum coarsely punctated with longitudinal unsculptured band medially; interspaces among punctures smooth; posterodorsal corner of propodeum dully angulate, not forming a distinct tooth in profile.

Petiole almost as long as wide, with strongly convex dorsal margin in profile: subpetiolar process low and small. Postpetole with convex dorsal margin highest at midlength in profile: posterodorsal margin convex.

Color: reddish brown: ocellar triangular area blackish brown: frons without dark brown spot.

Variation. Five paratype workers with the following measurements and indices: HL 0.50-0.53 mm; HW 0.43-0.48 mm: SL 0.29-0.31 mm; CI 93-95; SI 63-64; WL 0.60-0.63 mm; PL 0.2D-0.24 mm; PH 0.19-0.21 mm: DPW 0.14-0.16 mm: TL 2.0-2.2 mm.

Eye diameter varied from 0.12 to 0.13 mm.

Type Material
Holotype. Worker, Onoma, Yaku-shima. Kagoshima Pref., 16.VIII.1986, K. Kinomura leg. Paratypes. 2 females, 4 workers, same data as holotype; 2 females 4 workers, same locality, 17.VIII.1986, K. Kinomura leg.; 1 female, 2 workers, Nagata, Yaku-shima, Kagoshima Pref., 14.VIII.1986, K. Kinomura leg.; 3 workers, Yaku-shima, Kagoshima Pref., 19.III.1991, T. Satoh leg.; 1 female, 3 workers, Yaku-shima, Kagoshima Pref., 25.III.1981, 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
One of the seven deities of good fortune in Japanese folklore.

Determination Clarifications
This species corresponds to Vollenhovia sp. 6 ("Tatenashi-umematsuari" in Japanese) in Terayama and Yamauchi (1992).