Strumigenys traegaordhi

Known from litter-samples taken in montane rainforest and evergreen forest.

Identification
A member of the arnoldi complex in the Strumigenys arnoldi-group.

Bolton (1983) - The closest relative of traegaordhi is Strumigenys mesahyla, known from Zimbabwe. The two are superficially very similar but differ as follows.

Distribution based on Regional Taxon Lists
Afrotropical Region: Eritrea, South Africa.

Nomenclature

 *  traegaordhi. Strumigenys (Strumigenys) traegaordhi Santschi, 1913b: 257 (diagnosis in key) (w.) SOUTH AFRICA. Santschi, 1914e: 28 (w.); Emery, 1915g: 19 (q.). See also: Brown, 1954k: 27; Bolton, 1983: 396; Bolton, 2000: 598.

Worker
Bolton (1983) - TL 2.0-2.1, HL 0.54-0.55, HW 0.43, CI 78-80, ML 0.24, MI 44, SL 0.30, SI 70, PW 0.28, AL 0.59-0.60 (2 measured).

Apical fork of each mandible with 2 teeth, without intercalary teeth or denticles. Preapical armament of each blade of 2 teeth, the proximal distinctly longer than the distal and both teeth situated in the apical third of the length of the blade. Upper scrobe margins bordered by a narrow rim, the eyes not visible in full-face view. Eyes small, their maximum diameter distinctly less than the maximum width of the scape. Preocular notch absent, the ventral surface of the head without a preocular transverse groove or impression on each side. Antennal scapes shallowly curved in the basal third and slightly expanded in the median third, broadest at about the midlength. Leading edges of scapes shallowly convex and with a row of apically curved narrowly spoon-shaped hairs. Dorsum of head with ground-pilosity which becomes narrower and finer from front to back. Anteriorly, from the level of the posterior clypeal margin to about the level of the ends of the preocular laminae the hairs are spoon-shaped and quite broad, appearing almost scale-like in full-face view. Behind this level, and posteriorly over the highest point of the vertex to the occipital margin, the hairs are much narrower and less conspicuous, narrowly spatulate in shape. Hairs fringing the upper scrobe margins spoon-shaped and as large as those on the anterior portion of the cephalic dorsum. In profile the dorsum of the head with 6 standing hairs arranged in a row of 4 close to the occipital margin and a more anteriorly situated pair which are about at the highest point of the vertex. Dorsum of head reticulate-punctate. Pronotal humeri each with an elongate fine flagellate hair, the mesonotum with two pairs of standing hairs, the posterior pair of which is only half as long as the anterior pair. Ground-pilosity of dorsal alitrunk of sparse narrowly spatulate hairs similar to those on the head behind the highest point of the vertex. Metanotal groove present as a feeble line across the dorsum. Apical portions of propodeal teeth, which are free from the narrow infradental lamellae, very narrowly triangular and almost spiniform. Sides of alitrunk mostly smooth, the pleurae and sides of the propodeum with some peripheral punctures. Dorsal alitrunk reticulate-punctate, the pronotum also with some weak longitudinal rugulae. Dorsum of petiole node reticulate-punctate, the postpetiole smooth or at most with a few feeble punctures posteriorly. Spongiform appendages of pedicel segments moderately developed. In profile the petiole with a narrow ventral strip and a small lateral lobe, the postpetiole with the ventral lobe slightly smaller than the exposed area of the postpetiolar disc in profile. Basigastral costulae short but quite strongly defined. Petiole, postpetiole and gaster with standing stout hairs which are swollen or feebly clavate apically. Colour brown.

Bolton (2000) - TL 2.0-2.2, HL 0.54-0.57, HW 0.41-0.44, CI 76-80, ML 0.22-0.24, MI 40-44, SL 0.30-0.34, SI 70-77, PW 0.28-0.30, AL 0.59-0.63 (10 measured).

Type Material
Bolton (1983) - Syntype workers, SOUTH AFRICA: Natal, Piertermaritzburg (1. Triigardh) [examined].

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1917. A monograph of the Formicidae of South Africa. Part III. Myrmicinae. Annals of the South African Museum. 14: 271-402.
 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Emery C. 1915. Formiche raccolte nell'Eritrea dal Prof. F. Silvestri. Bollettino del Laboratorio di Zoologia Generale e Agraria della Reale Scuola Superiore d'Agricoltura. Portici 10: 3-26.
 * Finzi B. 1939. Materiali zoologici dell'Eritrea raccolti da G. Müller durante la spedizione dell'Istituto Sieroterapico Milanese e conservati al Museo di Trieste. Parte III. Hymenoptera: Formicidae. Atti del Museo Civico di Storia Naturale di Trieste 14: 153-168.
 * Madl M. 2019. Notes on the ant fauna of Eritrea (Insecta: Hymenoptera: Formicidae): type specimens deposited in the Natural History Museum Vienna (Austria) and a preliminary checklist. Ann. Naturhist. Mus. Wien, B 121: 9-18.
 * Santschi F. 1914. Meddelanden från Göteborgs Musei Zoologiska Afdelning. 3. Fourmis du Natal et du Zoulouland récoltées par le Dr. I. Trägårdh. Göteborgs Kungliga Vetenskaps och Vitterhets Samhälles Handlingar. 15: 1-44.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004