Oxyepoecus striatus

The type specimens were collected from three pitfall samples.

Identification
Delsinne et al. (2012) - Its worker morphology places this species within the vezenyii species-group [3]. The worker is a small specimen with longitudinal striae covering the promesonotum and transverse striae on the dorsopropodeum. The clypeal teeth are well defined and sharp. The gyne and male are unknown.

This species is a member of the vezenyii species-group defined principally in having a predominantly smooth and glossy dorsum of the head. It is very similar to the relatively common Oxyepoecus vezenyii, but can be easily distinguished as the promesonotum of O. vezenyii is nearly completely smooth and glossy (the dorsopropodeum of O. vezenyii has transverse striae as in O. striatus).

Oxyepoecus striatus appears most similar to Oxyepoecus browni, which has a similar sculptured promesonotum, short posterior propodeal face, moderately well-developed costulae between the frontal carinae, and a large lobe-like subpetiolar process. Oxyepoecus striatus can be separated as being smaller; the clypeal teeth are well defined, sharp, and directed anteriorly (not lobe-like and directed inward). The frontal lobes are more widely spaced than those of O. browni (separated by 0.11mm) and the head is covered by coarse punctures (except for the smooth medial area).

Distribution
Only known from the type locality.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Paraguay.

Castes
Known only from the worker caste.

Nomenclature

 *  striatus. Oxyepoecus striatus Mackay, W.P. & Delsinne, in Delsinne, et al. 2011: page, fig. 4 (w.) PARAGUAY.

Worker
Measurements of holotype; paratypes (n = 2) between parentheses: TL 1.58 (1.6-1.7), HL 0.46 (0.46–0.48), HW 0.35 (0.35-0.36), EL 0.05 (0.07-0.07), SL 0.29 (0.29–0.31), PL 0.06 (0.06-0.06), PW 0.16 (0.17-0.18), PPL 0.08 (0.09-0.09), PPW 0.19 (0.21-0.22),WL 0.51 (0.49–0.51); CI 76 (75-76), SI 63 (62–65).

Mandible with four teeth, with diastema (gap) between basal and subbasal teeth; lateral clypeal teeth well-developed but small, not lobe-like, directed anteriorly; eye small, with about 18 ommatidia, five ommatidia in greatest diameter; scape in repose failing to reach posterior border of head by about two maximum widths; sides of head nearly straight, parallel, frontovertexal margin slightly convex; pronotal shoulder slightly marked with stria; inferior pronotal process well developed; notopropodeal groove poorly developed; propodeal angles developed, acute; subpetiolar process well developed, lobe-like, directed ventrally, anterior and posterior faces of petiole nearly parallel; two subpostpetiolar angles present, anterior and posterior faces of postpetiole nearly parallel; as seen from above, postpetiole much broader than petiole, postpetiole slightly angulate laterally.

Erect hairs abundant on mandibles, clypeus, dorsal surface of head, dorsum of mesosoma, petiole, postpetiole, all surfaces of gaster, legs with semierect hairs; appressed pubescence sparse, few hairs noticeable on head and gaster.

Mandibles smooth and shiny, with few scattered punctures, most of dorsum of head with scattered coarse punctures, medial area smooth and glossy, mesonotum with longitudinal parallel striae, dorsopropodeum with fine transverse striae, lateropronotum mostly smooth and glossy, mesopleuron and lateropropodeum striolate, nodes of petiole and postpetiole smooth and glossy, posterior face of postpetiole transversely striolate, gaster smooth and glossy.

Body color. Concolorous Medium Reddish Brown.

Type Material
Holotype worker. Paraguay: Presidente Hayes: Rio Verde, Lat: S 23.22, Long: W 59.20, 15-16.X.2003, Delsinne T., 24-hour pitfall sample, specimen number 32606,. Paratypes. Same data as holotype, three workers, in three 24- hour pitfall samples, specimen numbers 29523, 29531, 29667, RBINS, INBP. Images of the specimen number 29531 are available at http://projects.biodiversity.be/ants.

Etymology
From Latin, stria, referring to the striae covering the dorsum of the mesosoma.