(Figs. 37, 42, 43)
Diagnosis. This species is distinguished from others in this species-group by the mesosternal armature, which consists of dentate ridges bearing two tubercles with the anterior greater in height than posterior (Fig. 37). Male. Coloration. Head, mesosoma and first metasomal segment ferruginous; antenna slightly paler. Metasomal segments 2–7 darker, dark ferruginous to piceous with violet-blue reflections, slightly lighter in coloration towards apex. Head and mesosoma uniform in color throughout.
Head. Ocellocular distance 1.1 X length of lateral ocellus; interocellular distance 0.8 X length of lateral ocellus. Mandible with three apical teeth and with large basal tooth; width at ventral tooth 1.1 X basal width of mandible, width at preceding sinus 0.6 X basal width of mandible, apical width 0.6 X basal width of mandible. Length first three flagellomeres: 2.6 X, 2.7 X and 2.6 X length of pedicel, respectively; width of first flagellomere 1.2 X length of pedicel.
Mesosoma. Mesosternum with dentate ridges, bearing two tubercles, height of anterior tubercle greater than that of posterior tubercle (Fig. 37). Marginal cell 2.2 X length of stigma. Stigma 0.8 X length of R 1 vein.
Metasoma. T 2 lacking apical margin with slightly raised area of denser fine punctures. Genitalia as in Figs. 42 and 43. Digitus with basal portion cylindrical; apical portion lobate, flattened, tapering toward apex.
Length. Holotype 17.4 mm. Variation ~14.0– 17.4 mm.
Type Specimens. Holotype. male; COSTA RICA: Guanacaste, Santa Rosa St. Park, 5.I. 1977, dry hill, D.W. Janzen (AEIC). Paratype: COSTA RICA: Guanacaste, Santa Rosa St. Park, 1 male, 3.III. 1978, dry hill, D.W. Janzen (AEIC).
Distribution. Known only from Central American dry forest of Guanacaste, Costa Rica.