Nesomyrmex fragilis

Nesomyrmex fragilis is distributed in tropical dry forests, disturbed forests, rainforests, and littoral rainforests in the Antsisarana region. A single sample (CASENT0134410) is known to have been collected in the Mahajanga region far south of the main distributional area of this species.

Identification
Csősz and Fisher (2016) - A member of the angulatus species-group. Workers of N. fragilis differ from those of Nesomyrmex clypeatus by having no median clypeal notch and from those of Nesomyrmex angulatus by the lack of an anterolateral pronotal corner. This species can be separated from Nesomyrmex devius, Nesomyrmex exiguus, Nesomyrmex gracilis, and N. hirtellus using morphometrics.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  fragilis. Nesomyrmex fragilis Csösz & Fisher, 2016: 25, figs. 11A-11C (w.q.) MADAGASCAR.

Worker
Body color: yellow. Body color pattern: concolorous. Absolute cephalic size (mm): 539 [469, 614] (n D 42). Cephalic length vs. maximum width of head capsule (CL/CWb): 1.229 [1.189, 1.278]. Postocular distance vs. cephalic length (PoOc/CL): 0.404 [0.389, 0.421]. Postocular sides of cranium contour frontal view orientation: converging anteriorly; parallel. Postocular sides of cranium contour frontal view shape: straight; feebly convex; convex. Vertex contour line in frontal view shape: straight; feebly convex. Vertex sculpture: main sculpture rugoso-reticulate, ground sculpture areolate. Gena contour line in frontal view shape: convex. Genae contour from anterior view orientation: converging; strongly converging. Gena sculpture: rugoso-reticulate with areolate ground sculpture. Concentric carinae laterally surrounding antennal foramen: absent. Eye length vs. absolute cephalic size (EL/CS): 0.260 [0.239, 0.276]. Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.409 [0.379, 0.430]. Longitudinal carinae on median region of frons: absent. Smooth median region on frons: absent. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.659 [0.615, 0.694]. Facial area of the scape absolute setal angle: 15-30°. Median clypeal notch: absent. Ground sculpture of submedian area of clypeus: present. Median carina of clypeus: present. Lateral carinae of clypeus: present. Median anatomical line of propodeal spine angle value to Weber length in lateral view: 20-27°. Spine length vs. absolute cephalic size (SPST/CS): 0.310 [0.257, 0.356]. Minimum spine distance vs. absolute cephalic size (SPBA/CS): 0.369 [0.327, 0.405]. Apical spine distance vs. absolute cephalic size (SPTI/CS): 0.377 [0.337, 0.424]. Propodeal spine shape: triangular, blunt. Anterolateral pronotal corner: absent. Metanotal depression: present, inconspicuous. Dorsal region of mesosoma sculpture: rugulose with areolate ground sculpture. Lateral region of pronotum sculpture: areolate ground sculpture, superimposed by dispersed rugae. Mesopleuron sculpture: areolate ground sculpture, superimposed by dispersed rugae. Metapleuron sculpture: areolate ground sculpture, superimposed by dispersed rugae. Petiole width vs. absolute cephalic size (PEW/CS): 0.407 [0.363, 0.460]. Dorsal region of petiole sculpture: ground sculpture areolate, main sculpture dispersed rugose. Postpetiole width vs. absolute cephalic size (PPW/CS): 0.470 [0.429, 0.507]. Dorsal region of postpetiole sculpture: ground sculpture areolate, main sculpture dispersed rugose.

Type Material
Holotype worker: Madagascar: Prov. Antsisarana, Nosy Be, Réserve Naturelle Intégrale de Lokobe, 6.3 km 112° ESE Hellville, 13.41933° S, 48.33117° E, 30 m, 19-24.iii.2001, collection code: BLF3496; CASENT0421396, Fisher et al. (CASENT0421396, ). Paratypes: five workers and a single gyne with the same locality data (CASC).

Etymology
This name fragilis (=fragile) refers to the small size of this species.