Strumigenys treptodens

Known from the holotype worker, which was noted as being collected from an alluvial forest.

Identification
Bolton (2000) - A member of the Strumigenys chapmani-group. At first glance treptodens appears to be a smaller, more slender and more extensively sculptured version of Strumigenys rotogenys, almost an intermediate between that species and Strumigenys chapmani. However, treptodens lacks the long flagellate gastral and basitarsal hairs characteristic of rotogenys. It differs from chapmani by having a much more strongly rolled under apicoventral tooth, more slender scapes, much longer basigastral costulae and a completely sculptured lateral alitrunk.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Philippines.

Nomenclature

 *  treptodens. Strumigenys treptodens Bolton, 2000: 770 (w.) BORNEO.

Worker
Holotype. TL 2.8, HL 0.86, HW 0.77, CI 90, ML 0.30, MI 35, SL 0.40, SI 52, PW 0.30, AL 0.70. Apicoventral tooth of the tridentate apical fork strongly rolled under, in dorsal view arising from the ventral surface of the mandible some distance behind the apex; with the appearance of a ventrally-arising preapical tooth. Apicoventral tooth with two small intercalary teeth arising from its dorsal surface. Scape slender, the leading edge sharp and shallowly convex but not lamellate. Ventrolateral margin of head with a deep, evenly concave preocular impression. Ventral surface of head behind eyes with a deep transverse impression that is separated from the preocular impression only by a narrow convex isthmus of cuticle immediately below the eye. In profile ventrolateral margin of head concave immediately behind the eye but not sharply marginate. Declivity of propodeum without a lamella. Cephalic dorsum densely reticulate-punctate. Cuticle within the deep scrobe finely reticulate-punctate. Entire dorsal alitrunk reticulate-punctate. Side of alitrunk reticulate-punctate everywhere; disc of postpetiole shagreenate to weakly punctate, not smooth. Basigastral costulae much longer than length of postpetiole disc, extending nearly half the length of the tergite. Cephalic dorsum without standing pilosity, with ground-pilosity of abundant short spatulate hairs. In full-face view similar hairs form a dense row along dorsolateral margin of head but apicoscrobal hair is longer and stouter. Promesonotum with closely applied curved spatulate hairs. Postpetiole with longer, more erect, more broadly spatulate hairs; gaster with numerous stout straight stiff standing hairs that are weakly broadened apically. Hind basi tarsi without flagellate hairs.

Type Material
Holotype worker, Malaysia: Sarawak, 4th Div., Gn. Mulu NP, vi-vii.1978, alluvial forest (M. Collins).