Strumigenys stenorhina

Nests under stones or decayed wood. Polygynous. (Japanese Ant Image Database)

Identification
Bolton (2000) – A member of the feae complex in the Strumigenys mayri-group. See Strumigenys exilirhina.

The species is similar to Strumigenys exilirhina, but distinguished by its long, straight mandibles (Japanese Ant Image Database).

Distribution based on Regional Taxon Lists
Palaearctic Region: Japan.

Nomenclature

 *  stenorhina. Strumigenys stenorhina Bolton, 2000: 893 (w.q.) JAPAN.

Worker
Holotype. TL 2.7, HL 0.77, HW 0.50, CI 65, ML 0.36, MI 47, SL 0.49, SI 98, PW 0.29, AL 0.75. Characters of the feae-complex. Preapical tooth triangular and slightly recurved, shorter than width of mandible at point where tooth arises. Outer margin of mandible in full-face view straight from close to base to level of preapical tooth; inner margin between same points straight or slightly convex. Upper scrobe margin with two freely laterally projecting flagellate hairs, one at level of eye and the other apicoscrobal. In full-face view the upper scrobe margins, from just in front of the level of the eyes to the scobe apex, evenly divergent posteriorly and only extremely feebly convex. Cephalic dorsum with 4-6 erect subflagellate or looped hairs along the occipital margin, a similar but shorter pair near level of highest point of vertex. Preocular notch absent but ventrolateral margin of head narrowed and somewhat constricted immediately in front of eye where it is shallowly and broadly concave. Maximum diameter of eye greater than the maximum width of the scape; eye with 4-5 ommatidia in the longest row. Pronotal humeral hair flagellate; pronotal dorsum finely reticulate to reticulate-punctate, may be somewhat effaced medially and have some extremely feeble longitudinal rugulae. Pronotal dorsum without erect hairs; mesonotum with 2 pairs of erect flagellate hairs. Dorsal surfaces of waist segments and first gastral tergite with flagellate hairs. Pleurae and side of propodeum smooth. One or two long fine erect flagellate hairs present on the dorsal (outer) surface of the hind basitarsus and another 1-2 on the hind tibia; similar pilosity present on the other legs. Petiole in profile with anterior face of node distinctly shorter than length of dorsum. Disc of postpetiole smooth.

Paratypes. TL 2.6-2.7, HL 0.73-0.78, HW 0.47-0.50, CI 63-66, ML 0.32-0.36, MI 45-48, SL 0.47-0.50, SI 98-102, PW 0.27-0.30, AL 0.72-0.78 (10 measured).

The single non-paratypic worker from China is slightly larger than the Japanese samples: HL 0.81, HW 0.52, CI 64, ML 0.40, MI 49, SL 0.54, SI 104, PW 0.30, AL 0.80.

Type Material
Holotype worker, Japan: Okinawa Pref., Ishigaki I., Yonehara, Yashiri n-tenboudai, 17.iii.1975 (K. Onoyama). Paratypes. 9 workers with same data as holotype [ series originally Vial #3 (KO colony #750317-6)]; numerous workers and queens in alcohol with same data as holotype but Vial #1 (KO colony #750317-13); several workers in alcohol with same data as holotype but 16.iii.1975, Vial #2 (KO colony #750316-3) (OMNH,, in Onoyama collection).

References based on Global Ant Biodiversity Informatics

 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Terayama M., S. Kubota, and K. Eguchi. 2014. Encyclopedia of Japanese ants. Asakura Shoten: Tokyo, 278 pp.