Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
Above images are of holotype. Additional images: holotype worker, dorsal view (small, large), label (small, large).
Costa Rica: Volcan Barva, 2000m.
Dorsum of mesosoma largely smooth; postpetiole broadly rounded posteriorly, not projecting over gaster; propodeal spines relatively short, subacute; face sculpture composed almost entirely of widely spaced foveae separated by smooth and shining spaces, rugae confined to median portion of face between frontal carinae, distance between foveae subequal to foveum diameter; very large species.
This species is a montane endemic, known only from uppermost limits of ant distribution on the Barva Transect in Braulio Carrillo National Park. It is known only from the type specimens, which occurred in four miniWinkler samples (leaf litter sifted from a 1 m2 forest floor patch) from one of the Project ALAS Winkler transects (http://purl.oclc.org/alas). It appears to be patchy in its local distribution: it occurred in only one of five Winkler transects at the site. Each transect was 250 m long, and the four occurrences of A. brenesi were widely separated along the transect in which it occurred.
Holotype worker: Costa Rica: Heredia Prov., 6 km ENE Vara Blanca (10°11'N 84°07'W), 2000 m elevation, 13.III.2002, leg. Project ALAS, specimen code JTLC000003382 (INBC).
4 Paratype workers: same data as holotype, specimen codes INB0003223968 (MCZC), INB0003223966 (LACM), INB0003223953 (UCDC), INB0003223935 (JTLC).
Worker: Mandible shining, coarsely striate, with five teeth on masticatory margin, masticatory margin meeting basal margin at obtuse angle, basal margin with stout triangular tooth at base near mandibular insertion; median lobe of clypeal plate a single blunt projection or slightly emarginate medially; lateral teeth of clypeal plate pronounced, triangular, interlocking with basal mandibular tooth when mandibles closed; anterior and medial face with striae mixed with large, widely-spaced foveae, grading posteriorly to area of large foveae separated by smooth, shiny interspaces, with foveae becoming sparser and smaller toward vertex margin; eye composed of 5-12 ommatidia, variably fused; hypostomal margin with small tooth; promesonotum smooth and shiny with sparse, shallow, piligerous foveae; mesopleuron and propodeum with large rugae, rugae widely spaced with smooth and shiny interspaces, rugae on dorsal face and upper half of posterior face of propodeum transverse, lower half of posterior face smooth and shining; promesonotum forming single convexity, dropping step-like to flat dorsal face of propodeum; propodeal spines triangular, acute, about as long as wide; petiolar and postpetiolar dorsa smooth except for piligerous puncta, shining; anteroventral margin of petiole lacking tooth, with at most a narrow longitudinal lamella; anteroventral margin of postpetiole with a strongly projecting transverse flange that appears as an acute tooth in side view; gaster smooth except for piligerous puncta, shining; mandibles, scapes, face, sides of head, femora, tibiae, petiolar and postpetiolar nodes, and gaster covered with abundant, long, subdecumbent pilosity; promesonotum covered with similar but somewhat more erect pilosity; dorsal face of propodeum with two long setae inclined forward, otherwise pilosity sparse; color dark red brown.
Measurements (holotype): HL 0.814, HW 0.698, SL 0.519, MeL 0.822.
Named for Danilo Brenes M., Project ALAS Parataxonomist from 1992 to 2006.
In Fernández (2003) this species keys to A. foveolatus. It is a large montane version of A. foveolatus, differing in the much larger size and the step-like juncture of promesonotum and propodeum. In A. foveolatus the mesosoma forms a single arched convexity.
Fernández C., F. 2003. Revision of the myrmicine ants of the Adelomyrmex genus-group (Hymenoptera: Formicidae). Zootaxa 361:1-52.
Longino, J. T. 2006. New species and nomenclatural changes for the Costa Rican ant fauna (Hymenoptera: Formicidae). Myrmecologische Nachrichten 8:131-143.
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.email@example.com
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