This species occurs in mid-elevation wet forest habitats. So far it is known only from the Volcan Barva transect in Braulio Carrillo National Park, from 1000 - 1100 m elevation. I collected a nest in a treefall gap, in the 1.25 cm diameter live stem of a melastome vine. It contained 32 workers, 1 dealate queen, and abundant brood of various sizes. One specimen was collected in a Project ALAS sweep sample. Workers have been collected as foragers on low vegetation. (Longino 2006)
Longino (2006) - This species keys to Nesomyrmex pleuriticus in Kempf (1959). The two species have a parapatric distribution on the Barva Transect in Braulio Carrillo National Park, N. pleuriticus occurring at La Selva Biological Station and the 500 m site, N. vargasi occurring around the 1100 m site. Nesomyrmex vargasi differs from N. pleuriticus in the much smoother and shinier surface sculpture.
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- vargasi. Nesomyrmex vargasi Longino, 2006b: 136, figs. 11, 12 (w.q.) COSTA RICA.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Holotype: HL 0.764, HW 0.722, SL 0.603, MeL 0.938.
Antenna 11-segmented; eye with about 11 ommatidia across greatest diameter; mandible smooth and shiny to weakly striate; all surfaces of body shiny; generally smooth and polished except for about 5 longitudinal rugae between eye and antennal insertion, about 6 longitudinal rugae on promesonotum, a few longitudinal rugulae on dorsal face of propodeum, about 3 longitudinal rugae on ventral half of side of pronotum, irregular rugulae on katepisternum and side of propodeum, about 4 longitudinal rugae on side and dorsum of petiole; side and dorsum of pronotum flat, meeting at carinate right angle; propodeal spiracles large, horizontal, opening dorsally; inferior propodeal lobes large, produced as an acute but rounded angle; anteroventral margin of petiole with acute, ventrally-directed tooth; scapes with abundant erect setae, these shorter than maximum width of scape, and with abundant underlying suberect pubescence; face with abundant short erect setae, these about as long as setae on scapes; in full face view abundant short suberect setae projecting from sides of head and margin of vertex; mesosomal and petiolar dorsa with abundant flexuous setae, these longer than those on face, longest about as long as propodeal spines; postpetiole, gastral dorsum, femora, and tibiae with abundant erect setae, these about as long as those on scapes and face; color red brown.
Holotype worker: Costa Rica: Heredia Prov., 15 km SSE La Virgen (10° 17' N, 84° 05' W), 1000 m elevation, 12.VII. 1986, leg. J. Longino#1365, specimen code INBIOCRI0 02281227 (Instituto Nacional de Biodiversidad). Paratypes: 1 worker and 1 dealate queen on same pin, same data as holotype, specimen (pin) code INBIOCRI002 281 28 (John T. Longino Collection); 2 5 workers, same data as holotype but 9.VII.1986, leg. J. Longino#1380-s, JTLC000008515 (Los Angeles County Museum of Natural History), JTLC00000 8516 (Museum of Comparative Zoology), JTLC000008517 (University of California, Davis), JT LC000008518 (California Academy of Sciences), JTLC000008519 (Naturhistorisches Museum Wien, Vienna); 1 worker, Costa Rica: Heredia Prov., 16 km SSE La Virgen (10°16' N 84°05' W), 1100 m elevation, leg. R. Vargas C. 11/RG/RVC/009, INB0003225385 (INBC); 1 worker, same data but 15 - 17.XI.2000, leg. J. Longino#4365-s, INBIOCR I0022 82019 (National Museum of Natural History); 1 worker same data but 11.II.2001, leg. J. Longino#4385-s, LACM ENT 144699 (The Natural History Museum).
Named for Ronald Vargas C., ALAS Parataxonomist from 1992 to 2005.
- Longino, J.T. 2006. New species and nomenclatural changes for the Costa Rican ant fauna (Hymenoptera: Formicidae). Myrmecologische Nachrichten. 8:131–143.