Strumigenys sevesta

Identification
The only species in the group completely to lack spongiform tissue ventrally on the petiole. This, coupled with the absence of a lateral spongiform lobe on the petiole node, is diagnostic.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica.

Nomenclature

 *  sevesta. Strumigenys sevesta Bolton, 2000: 518, figs. 307, 340 (w.) COSTA RICA.

Worker
Holotype. TL 2.8, HL 0.70, HW 0.56, CI 80, ML 0.42, MI 60, SL 0.47, SI 84, PW 0.35, AL 0.73. Mandible without trace of preapical dentition. Apicoscrobal hair and pronotal humeral hair flagellate. Both pairs of erect hairs on cephalic dorsum stiff and simple; mesonotum with a similar but more acutely pointed pair of erect hairs. Petiole, postpetiole and first gastral tergite with stiff simple hairs that are erect, shallowly curved and mostly acute apically. Pronotal dorsum reticulate-punctate with superimposed fine rugular sculpture. Mesopleuron smooth, metapleuron and side of propodeum reticulate-punctate. Propodeum with a pair of narrow short spines that are subtended by vestigial carinae down the declivity; no lamellae present and propodeal lacuna absent. Ventral surface of petiole without spongiform tissue except for a minute process at extreme posteroventral angle. Lateral spongiform lobe of petiole node absent or no more than a slight thickening of the apex of the posterior collar. In profile lateral spongiform appendage of postpetiole reduced to a narrow cuticular collar; ventral spongiform lobe very small, much smaller than the area of exposed cuticle of the disc. Petiole node in dorsal view broader than long, reticulate-punctate; disc of post petiole finely reticulate-punctate everywhere. Basigastral costulae minute and feebly defined, much shorter than length of postpetiole disc.

Paratypes. TL 2.7-3.0, HL 0.68-0.74, HW 0.52-0.61, CI 76-82, ML 0.41-0.44, MI 58-62, SL 0.46-0.49, SI 80-88, PW 0.31-0.36, AL 0.70-0.80 (10 measured). As holotype but in some the apices of the mesonotal standing hairs, and of some on the gaster, may be markedly thinner than their shafts and more strongly curved or even hooked. Preapical dentition is uniform throughout type-series, but given its variability in other species of the group some variation should perhaps be expected.

Type Material
Holotype worker, Costa Rica: Provo Puntarenas, Monteverde, 1360 m., 10°18'N, 84°48'W, 16.iv.1988, forest litter sample, ground, #1997-S (J. Longino).

Paratypes. Costa Rica: 2 workers from same locality but 1500 m., 10.xii.1987, cloud forest litter sample, ground, #1972-S (J. Longino); 1 worker from same locality but 1300 m., 21.xii.1986, wet forest litter sample, #1487-S (J. Longino); 2 workers with same data but 1500 m., 16.iv.1989, wet forest ex sifted leaf litter, #2467-S and #2468-S (J. Longino); 1 worker, Provo Heredia, 1 3 km. SSW Pto Viejo, 10°21'N, 84°03'W, 300 m., 17.vii.1986, wet forest litter sample, #1390-S (J. Longino); 3 workers, Provo Alajuela, 3 km. E Monteverde, 10°18'N, 84°47'W, 1400 m., 26.iv.1990, wet forest ex sifted leaf litter, #2674-S (J. Longino); 2 workers, Provo Alajuela, Rio Penas Biancas, 10°19'N, 84°43'W, 800 m., 26-28.iv.1987, wet forest ex sifted leaf litter, #1579-S (J. Longino).