Nesomyrmex minutus Csosz & Fisher

Csosz, Sandor & Fisher, Brian L., 2016, Taxonomy of Malagasy Nesomyrmex brevicornis species-group using conventional morphology-based approach, ZooKeys 616, pp. 125-159 : 151-153

Nesomyrmex minutus Csosz & Fisher sp. n. Figs 34-36 , 37 , Table 1

Type material investigated.

Holotype: CASENT0071633, collection code: BLF14082, Réserve Speciale Manombo 24.5 km 228° Farafangana, -23.01583°, 47.719°, alt 30 m, B.L. Fisher et al., 04.22.2006, (1w, CASC, CASENT0071633);

Paratypes: 21 workers, 16 gynes, and one male from the same locality under CASENT codes:

CASENT0071611, collection code: BLF14077, (1w, 1Q, CASC); CASENT0071616, collection code: BLF14066, (1w, CASC, CASENT0071616); CASENT0071632, collection code: BLF14076, (1w, 1Q, CASC); CASENT0071639, collection code: BLF14100, (1w, CASC); CASENT0071640, collection code: BLF14081, (1w, 1Q, CASC); CASENT0071644, collection code: BLF14073, (1w, 1Q, CASC); CASENT0071646, collection code: BLF14074, (1w, 1Q, CASC); CASENT0071647, collection code: BLF14071, (1w, 1Q, CASC); CASENT0071650, collection code: BLF14111, (1w, CASC); CASENT0071657, collection code: BLF14083, (1w, 1Q, CASC); CASENT0071658, collection code: BLF14067, (1w, CASC); CASENT0071662, collection code: BLF14064, (1w, 1Q, CASC); CASENT0071667, collection code: BLF14078, (1w, CASC); CASENT0071668, collection code: BLF14079, (1w, 1Q, CASC); CASENT0071673, collection code: BLF14072, (1w, 1Q, CASC); CASENT0071676, collection code: BLF14070, (1w, CASC); CASENT0071714, collection code: BLF14084, (1w, 1Q, CASC); CASENT0071720, collection code: BLF14069, (1w, CASC); CASENT0071721, collection code: BLF14080, (1w, 1Q, CASC); CASENT0071725, collection code: BLF14075, (1w, CASC); CASENT0071656, collection code: BLF14068, (1w, 1m, CASC); CASENT0071675, collection code: BLF14063, (1Q, CASC); CASENT0071645, collection code: BLF14073, (1Q, CASC); CASENT0071636, collection code: BLF14076, (1Q, CASC); CASENT0071659, collection code: BLF14083, (1Q, CASC);

Etymology.

The name ( minutus ) refers to the small tiny appearance of workers of this species.

Diagnosis in key.

Description of workers. Body color: yellow. Body color pattern: body concolorous, first gaster tergite darker. Absolute cephalic size: 469 [405, 530]. Cephalic length vs. maximum width of head capsule (CL/CWb): 1.30 [1.22, 1.36]. Postocular distance vs. cephalic length (PoOc/CL): 0.52 [0.51, 0.54]. Postocular sides of cranium contour frontal view orientation: converging posteriorly. Postocular sides of cranium contour frontal view shape: broadly convex. Vertex contour line in frontal view shape: straight. Vertex sculpture: main sculpture absent, ground sculpture imbricate, shiny. Setal pits on head dorsum: inconspicuous with obscure demarcation. Gena contour line in frontal view shape: convex. Genae contour from anterior view orientation: converging. Gena sculpture: rugoso-reticulate with areolate ground sculpture; ground sculpture areolate, main sculpture costulate. Concentric carinae laterally surrounding antennal foramen: present. Eye length vs. absolute cephalic size (EL/CS): 0.25 [0.22, 0.28]. Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.36 [0.33, 0.39]. 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): 0.57 [0.53, 0.61]. Median clypeal notch: present. Ground sculpture of submedian area of clypeus: present. Median carina of clypeus: absent. Metanotal depression: present. Dorsal region of mesosoma sculpture: imbricate, main sculpture absent. Lateral region of pronotum sculpture: imbricate, main sculpture absent; inconspicious areolate ground sculpture, main sculpture dispersed costate. 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 [0.20, 0.23]. Dorsal region of petiole sculpture: ground sculpture areolate, main sculpture absent. Postpetiole width vs. absolute cephalic size (PPW/CS): 0.33 [0.30, 0.35]. Dorsal region of postpetiole sculpture: ground sculpture smooth, main sculpture absent. Surface of the first gastral tergite: imbricate sculpture absent.

Distribution.

This species is known from rainforests of a single locality in the southeastern coast of Madagascar ( Fig. 37 ), where it appears to be exclusively associated with the host plant Macphersonia gracilis ( Sapindaceae ). We know little about the ecology of the association. Unlike other tropical regions, very few ant plant associations are known from Madagascar. The only known ant assocations are from notheastern Madagascar, where three species in the plant genus Gravesia Naudin, 1851 ( Melastomataceae ) are often occupied by Tetramorium silvicola Hita Garcia & Fisher, 2014 and Vitsika breviscapa Bolton & Fisher, 2014.

Figures

Figures 37. Geographic distribution of Nesomyrmex minutus sp. n .. The known localities of Nesomyrmex minutus sp. n. in Madagascar.

Figures 34 - 36. Nesomyrmex minutus sp. n. holotype worker (CASENT 0071633). Head in full-face view (34), dorsal view of the body (35), lateral view of the body (36).