Nesomyrmex nitidus

This species typically occurs in Madagascar’s rain forests at lower altitudes between 10 and 1550 meter, mean: 383m. This species is known to forage in low vegetation, nests can often be found in dead twigs, stems above ground or rarely in rotten logs at higher elevations.

Identification
A member of the madecassus species-group.

Csősz & Fisher (2016) - Workers of N. nitidus cannot be confused with Nesomyrmex gibber because the conspicuous mesothoracic hump that is a diagnostic character of the latter species is absent in N. nitidus workers. This species also can be easily separated from dark phenotypes of Nesomyrmex madecassus based on color: the dark madecassus phenotypes are dark brown but the workers of N. nitidus are light yellow. Morphometric ratio (PoOC/CW) and discriminant D4 function helps to separate N. nitidus from ocher madecassus phenotypes; further details are given in Diagnosis under N. madecassus.

The workers of this species are the most similar to that of Nesomyrmex flavus. The broadly overlapping elevational distribution as well as qualitative and quantitative traits of N. flavus and N. nitidus workers hamper easy separation. A simplified discriminant D2 function with a greatly reduced character set for safe separation is provided in the diagnosis section of N. flavus.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  nitidus. Nesomyrmex nitidus Csősz & Fisher, 2016: 124, figs. 13-15 (w.q.) MADAGASCAR.

Worker
Body color: yellow. Body color pattern: Body concolorous. Absolute cephalic size: 496 [460, 574]. Cephalic length vs. maximum width of head capsule (CL/CWb): 1.23 [1.16, 1.35]. Postocular distance vs. cephalic length (PoOc/CL): 0.48 [0.46, 0.50]. Postocular sides of cranium contour frontal view orientation: converging posteriorly. Postocular sides of cranium contour frontal view shape: convex. Vertex contour line in frontal view shape: straight; slightly concave. Vertex sculpture: main sculpture inconspuous, ground sculpture smooth. Gena contour line in frontal view shape: convex. Genae contour from anterior view orientation: 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): 0.26 [0.23, 0.27]. Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.31 [0.29, 0.33]. Longitudinal carinae on median region of frons: absent. Smooth median region on frons: present. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.74 [0.69, 0.78]. Median clypeal notch: variable. Ground sculpture of submedian area of clypeus: smooth; present. Median carina of clypeus: variable. Lateral carinae of clypeus count: present. Metanotal depression: va-riable. Dorsal region of mesosoma sculpture: areolate ground sculpture, superimposed by dispersed rugae. Lateral region of pronotum sculpture: ground sculpture areolate, main sculpture absent. Mesopleuron sculpture: ground sculpture areolate, main sculpture absent. Metapleuron sculpture: ground sculpture areolate, main sculpture absent. Petiole width vs. absolute cephalic size (PEW/CS): 0.22 [0.19, 0.24]. Anterior profile of petiolar node contour line in lateral view shape: concave. Dorso-caudal petiolar profile contour line in lateral view shape: convex. Dorsal region of petiole sculpture: ground sculpture smooth, main sculpture absent. Postpetiole width vs. absolute cephalic size (PPW/CS): 0.33 [0.30, 0.36]. Dorsal region of postpetiole sculpture: ground sculpture smooth, main sculpture dispersed rugose.

Type Material
Holotype: CASENT0163151, collection code: BLF24792: Madagascar, Prov. Toamasina, Réserve Spéciale Ambatovaky, Sandrangato river, N -16.81753, E 49.29498, alt 360 m, B.L. Fisher et al. 2_25_2010, (1w, ); Paratypes: two workers and one gyne from the same locality under CASENT codes: CASENT0163112, collection code: BLF24794: Madagascar, Prov. Toamasina, Réserve Spéciale Ambatovaky, Sandrangato river, N -16.81753, E 49.29498, alt 360 m, B.L. Fisher et al.2_25_2010, (1w, CASC); CASENT0162145, collection code: BLF24570: Madagascar, Prov. Toamasina, Réserve Spéciale Ambatovaky, Sandrangato river, N -16.7633, E 49.26692, alt 520 m, B.L.Fisher et al.2_26_2010, (1w, CASC); CASENT0161445, collection code: BLF25001: Madagascar, Prov. Toamasina, Réserve Spéciale Ambatovaky, Sandrangato river, N -16.81209, E 49.29216, alt 460 m, B.L. Fisher et al.2_22_2010, (1q, CASC).