Strumigenys sauteri

Known from a few collections, all from rainforest litter-samples. In Hong Kong it is a widespread species found in diverse habitats including grasslands, shrublands, plantations (e.g. L. confertus), urban forest remnants, secondary forest, and Feng Shui woods. Specimens were collected at elevation ranging from 19 to 630 m (Tang et al., 2019).

Identification
Bolton (2000) - A member of the Strumigenys sauteri-group. Within this group the three species sauteri, Strumigenys arges and Strumigenys brontes form a complex of closely related forms. All share the dentition described in the introduction to the group and have a characteristic clypeal shape. In full-face view the lateral margins are convex, especially in the anterior half where they curve inwards toward the anterolateral angles; the latter are narrowly rounded and project strongly forward. Between them the anterior margin proper is deeply and evenly concave. The outer margins of the fully closed mandibles intersect the anterior clypeal margin in its concave portion, just mesad of the anteriormost points of the anterolateral clypeal angles.

Of the three species arges and sauteri have the leading edge of the scape with an evenly convex shallow curvature in the basal half. In brontes the leading edge is very broad at about the basal third where it forms a strongly prominent angle, distal to which the margin is shallowly concave. S. brontes also completely lacks basigastral costulae, which in sauteri and arges are visible at least laterally on the limbus. The last two species separate quite well by their sculpture. In sauteri the metapleuron and side of the propodeum are uniformly finely punctate, whilst in arges these areas are mostly or entirely smooth and shining. Most populations of sauteri also have the mesopleuron punctate at least in part, though a few are known where this sclerite is smooth. In arges the mesopleuron always lacks punctate sculpture.

The depository of the holotype worker of sauteri was unknown for many years, and Forel’s misleading original description, in which he miscounted the number of antennal segments, did nothing to facilitate the establishment of its real identity. The rediscovery and redescription of the holotype by Brown & Boisvert (1979) fixed its identity and showed its relationship to the Japanese species Strumigenys canina. Separation of these two is discussed under the latter name.

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

Nomenclature

 *  sauteri. Pentastruma sauteri Forel, 1912a: 51 (w.) TAIWAN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 127. See also: Brown & Boisvert, 1979: 203. See also: Bolton, 2000: 464.

Type Material
Bolton (2000) - Holotype worker, TAIWAN: Pilam (H. Sauter) (IPAL) [not seen].