Nesomyrmex tamatavensis

This species is known to occur in rainforests from sea level to 1100 m predominantly in the northeastern part of Madagascar. The only known locality of this species in the southwestern Toliara region (Forêt Classée d'Analavelona, NNW Mahaboboka) is in an isolated rainforest surrounded by dry forest; this rainforest is a relic of the formerly widespread rainforest now found primarily in the east.

Identification
A member of the sikorai species-group.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  tamatavensis. Nesomyrmex tamatavensis Csösz & Fisher, 2016b: 27, figs. 3, 16A-C (w.m.) MADAGASCAR.

Worker
Body color: yellow to brown. Body color pattern: concolorous. Absolute cephalic size: 699 μm [634, 750]. Cephalic length vs. maximum width of head capsule (CL/CWb): 1.155 [1.119, 1.182]. Postocular distance vs. cephalic length (PoOc/CL): 0.433 [0.411, 0.449]. Postocular sides of cranium contour, anterior view orientation: converging posteriorly. Postocular sides of cranium contour, anterior view shape: convex. Vertex contour line in anterior view shape: straight to feebly convex. Vertex sculpture: main sculpture inconspicuous, ground sculpture smooth. Gena contour line in anterior view shape: convex. Gena contour from anterior view orientation: strongly converging. Gena sculpture: rugoso-reticulate with feeble areolate ground sculpture. Concentric carinae laterally surrounding antennal foramen: present. Eye length vs. absolute cephalic size (EL/CS): 0.258 [0.243, 0.284]. Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.329 [0.318, 0.347]. Longitudinal carinae on median region of frons: present or absent. Smooth median region on frons: present. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.798 [0.773, 0.832]. Median clypeal notch: present. Median carina of clypeus: absent. Spine length vs. absolute cephalic size (SPST/CS): 0.388 [0.364, 0.43]. Minimum spine distance vs. absolute cephalic size (SPBA/CS): 0.244 [0.221, 0.282]. Apical spine distance vs. absolute cephalic size (SPTI/CS): 0.303 [0.273, 0.35]. Propodeal spine shape: strongly bent. Apical distance of pronotal spines vs. absolute cephalic size (PSTI/CS): 0.739 [0.708, 0.78]. Metanotal depression: present. Dorsal region of mesosoma sculpture: rugose with smooth ground sculpture. Lateral region of pronotum sculpture: inconspicuously areolate ground sculpture, main sculpture rugoso-reticulate. Mesopleuron sculpture: smooth ground sculpture, superimposed by dispersed rugulae. Metapleuron sculpture: fine areolate ground sculpture, superimposed by dispersed rugulae. Petiole width vs. absolute cephalic size (PEW/CS): 0.243 [0.208, 0.27]. Dorsal region of petiole sculpture: ground sculpture inconspicuously areolate, main sculpture rugoso-reticulate. Postpetiole width vs. absolute cephalic size (PPW/CS): 0.363 [0.338, 0.385]. Dorsal region of postpetiole sculpture: ground sculpture smooth, main sculpture dispersed rugose.

Type Material
Holotype worker: Madagascar: Prov. Toamasina, Montagne d'Akirindro 7.6 km 341° NNW Ambinanitelo, 600 m, -15.28833 N, 49.54833 E, 17. iii.2003, collection code: BLF8390; CASENT0496292, Fisher et al., ex dead twig above ground, rainforest (, CASENT0496292). Paratypes: 5 workers and a male with the same label data with the holotype with CASENT codes: CASENT0763559, BLF8390, (2w, CAS); CASENT0496293, BLF8390, (3w, CAS); CASENT0496294, BLF8390, (3w, CAS); CASENT0496295, BLF8390, (1q, 1m, CAS).

Etymology
Tamatave is the French name of Toamasina, the capital of the Atsinanana region, where this species is abundant.