Nesomyrmex vannoorti

Specimens were collected from pitfall traps, yellow pan traps and from sweeping in Nama-Karoo on dolerite soils and from Ruschia spinisa/Eriocephalis veld.

Identification
Mbanyana and Robertson (2008) - A member of the simoni species-group. Nesomyrmex vannoorti is similar-looking to Nesomyrmex ruani, Nesomyrmex nanniae and Nesomyrmex entabeni. In all of them the unarmed propodeum forms an even convexity and colour is medium to dark brown. It is distinguished from the three latter species by having hairs on the propodeum.

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

Nomenclature

 *  vannoorti. Nesomyrmex vannoorti Mbanyana & Robertson, 2008: 54, figs. 3j-l (w.) SOUTH AFRICA.

Worker
Holotype. HL 0.669, HW 0.521, HW1 0.561, CI 78, SL 0.441, SI 85, PW 0.382, ML 0.818, EL 0.197 EI 38.

Mandibles with longitudinal striations. Clypeus with longitudinal striations, with central and posterior region of median portion smooth to faintly reticulate. Anterior clypeal margin evenly convex and with a projecting translucent lamella medially. Large eyes with 16 ommatidia in the longest row. Scapes of moderate length (SI 85). Head in full face-view hind margin shallowly convex. Promesonotum in profile evenly convex and metanotal groove conspicuously impressed. Propodeum unarmed; forming an even convexity with declivity. Anterior peduncle with a small tooth-like subpetiolar process. Petiolar node in profile evenly convex; posterior to the node is a moderately broad cylindrical portion of the petiole. Postpetiole in profile low and rounded. Dorsum of head with faint reticulate pattern and faint longitudinal striations between the eyes and behind the antennal insertions. Promesonotum finely reticulate, propodeal dorsum reticulate-punctate. Petiolar node and postpetiole finely reticulate pattern. First gastral tergite with a very short basal costulae and the rest of the tergite smooth and shining. Dorsum of head with short erect hairs mostly concentrated along two longitudinal lines. The venter of head with five straight hairs and two curved hairs. Promesonotal dorsum with at least four pairs of short, erect hairs, acute apically. Propodeum with two pairs of erect hairs, petiolar node with two pairs of suberect acute hairs apically and postpetiole with two pairs of suberect hairs. Regularly spaced suberect hairs on the gastral tergite and sternite. Head and gaster dark brown, with mesosoma and nodes light brown in colour.

Paratypes. HL 0.620–0.698, HW 0.462–0.582, HW1 0.502–0.610, CI 75–81, SL 0.398–0.492, SI 80–93, PW 0.352–0.423, ML 0.751–0.944, EL 0.177–0.236, EI 33–42 (22 of 45 measured).

Same as holotype except the following differences: Mandibles either with longitudinal striations or smooth and shining. Dorsum of head smooth or with faint reticulate pattern between the eyes; fine longitudinal striations between the eyes and behind the antennal insertions present. Promesonotum either finely reticulate, or smooth and shining, with a fine, barely evident, inlaid reticulate pattern. The venter of head with 3–5 long hairs. Promesonotal dorsum with 3–4 pairs of short suberect hairs. Base of first gastral tergite either with or without costulae. Colour either uniformly medium brown or head and gaster dark brown, with mesosoma and nodes light brown.

Type Material
Holotype: South Africa: Western Cape: Avondale farm, 32°15.00’S 22°56.60’E, 19 April 2001, S. van Noort, BW01-A1-S82, SAM-HYM-C019103. Paratypes: South Africa: Western Cape: Avondale farm, 32°15.00’S 22°56.60’E, 22–29 April 2001, H.G. Robertson&RTourle, BW01-A1-P09, SAM-HYM-C019093; Avondale farm, 32°15.00’S 22°56.60’E, 22–29 April 2001, S. van Noort & D. Larsen, BW01-A1-Y95, SAM-HYM-C019095; Avondale farm, 32°13.33’S 22°57.53’E, 22–29 April 2001, Robertson & R. Tourle, BW01-A3-P08, SAM-HYMC019096; Avondale farm, 32°14.31’S 22°58.59’E, 22–29 April 2001, H.G. Robertson & R. Tourle, BW01-A4-P07, SAM-HYM-C019098; Avondale farm, 32°14.31’S 22°58.59’E, 22–29 April 2001, H.G. Robertson & R. Tourle, BW01-A4-P09, SAM-HYM-C019098; Avondale farm, 32°15.00’S 22°56.60’E, 22–29 April 2001, H.G. Robertson & Tourle, BW01-A1-P09, SAM-HYM-C019093; Avondale farm, 32°14.31’S 22°58.59’E, 22–29 April 2001, S. van Noort & D. Larsen, BW01-A4-Y107, SAM-HYM-C019106; Avondale farm 32°14.31’S 22°58.59’E, 22–29 April 2001, H.G. Robertson & R. Tourle, BW01-A4-P02, SAM-HYMC019097; Avondale farm, 32°14.31’S 22°58.59’E, 22–29 April 2001, S. van Noort & D. Larsen, BW01-A4-Y103, SAMHYM-C019107; Tierberg near Prince Albert, 33°10’0”S 22°16’0”E, 12 September 1995, H. Adie, Ref. no. 094, SAM-HYM-C008454; Tierberg near Prince Albert, 33°10’0”S 22°16’0”E, 11 September 1995, H. Adie, SAM-HYM-C008785.

Etymology
Named after our colleague Dr Simon van Noort who is a Curator of Entomology at Iziko South African Museum and who collected the holotype.

References based on Global Ant Biodiversity Informatics

 * Hita Garcia F., Mbanyana N., Audisio T. L., and G. D. Alpert. 2017. Taxonomy of the ant genus Nesomyrmex Wheeler (Formicidae, Myrmicinae) in the Afrotropical region, with a review of current species groups and description of a new species of the N. angulatus group from Mozambique. European Journal of Taxonomy 258: 1–31.
 * Mbanyana N., and H. G. Robertson. 2008. Review of the ant genus Nesomyrmex (Hymenoptera: Formicidae: Myrmicinae) in southern Africa. African Natural History 4: 35-55.