Oxyepoecus rosai

Specimens were attracted to sardine baits or recovered from the leaf-litter using Winkler extractors.

Identification
Albuquerque & Brandão (2009) - In the Rastratus species-group, O. rosai workers present the integument of mesopleuron and lateral pronotum irregularly sculptured, as in Oxyepoecus myops, but differs from the later by the larger compound eyes, and by the smooth integument on the head vertex and lateral portions of the pronotum, petiolar node, and postpetiole.

Distribution
The distribution of O. rosai includes only localities at South and Southeastern Brazil, between São Paulo and Santa Catarina States.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Castes
Males are unknown.

Nomenclature

 *  rosai. Oxyepoecus rosai Albuquerque & Brandão, 2009: 304, figs. 5a-c, 8 (w.q.) BRAZIL.

Worker
(Holotype and paratypes (N = 33) variation within brackets): t.l. = 2.33 (2.30‑2,40); h.l. = 0.60 (0.60‑0.63); h.w. = 0.45 (0.43‑0.48); s.l. = 0.35 (0.35‑0.38); m.l.e. = 0.10 (0.10‑0.13); m.w.pr. = 0.33 (0.30‑0.35); a.l. = 0.65 (0.65‑0.68); h.f.l. = 0.35 (0.35‑0.38); m.w.p. = 0.20 (0.20‑0.23); m.w.pp. = 0.25 (0.25‑0.28); c.i. 75 (72‑76). Color chestnut brown, gaster fuscous. Irregularly costulae and rugulate sculpture covering almost all head dorsum integument, except by clypeus, around antennal insertions and vertex; almost all mesosoma irregularly reticulate, except antero-lateral portion of pronotum, area around propodeal spiracle, petiolar peduncle dorsum, node of petiole and postpetiole smooth and shining. Hairs moderately abundant, short and subdecumbent, on head dorsum mesad oriented, anteriorly curved on head sides; dorsum of mesosoma with suberect hairs, backwards oriented on petiolar and postpetiole nodes; gaster without interspersed shorter and decumbent hairs.

Head (f.f.v.): Mandible with basal border slightly shorter than chewing border, basal tooth separated from subbasal tooth by shallow diastema. Anterior tooth of clypeus mesially directed with smaller lateral denticle. Frontal carinae gently convex and subparallel over antennal sockets, maximum width between outer edges always less than one fourth head width. Compound eye with 4‑5 facets r.g.d., height less than oculomalar; total number of ommatidia not exceeding 13. Antennal scape fails to reach vertexal corner by distance approximately equal to maximum scape width. Funnicular segment I longer than II‑V combined, segments II‑VII distinctly broader than long, VIII and IX as long as broad. Vertexal margin straight.

Mesosoma with promesonotum gently rounded on shoulders. Metanotal groove almost indistinct (p.v.). Basal face of propodeum immarginate on sides, posteriorly with a small tooth. Declivous face laterally weakly carinate.

Petiole pedunculate, node scarcely compressed antero-posteriorly (d.v.) club shaped; subpetiolar process with a small, blunt and obliquely oriented denticle anteriorly. Postpetiole very broad, not as high as petiolar node; subpostpetiolar process shaped as small, transversal crest.

Queen
(variation of gynes paratypes, N = 2): t.l. = (2.80‑2.93); h.l. = (0.60‑0.63); h.w. = (0.50‑0.53); s.l. = (0.40‑0.43); m.l.e. = (0.25‑0.30); m.w.pr. = (0.43‑0.45); a.l. = (0.70‑0.73); h.f.l. = (0.38‑0.40); m.w.p. = (0.18‑0.20); m.w.pp. = (0.33‑0.35); c.i. (83‑85). Almost same workers character states, with caste differences of: three ocelli very small, with same diameter, approximately half minimum thickness of antennal scape, compound eye with 8 facets r.g.d., and circa 40 in whole eye.

Type Material
Holotype: worker. Brazil: São Paulo: Salesópolis [23°39’S, 45°53’W], 20‑26.x.1997, C. Klingenberg & C.I. Yamamoto col., attracted to sardine baits; deposited in. Paratypes (all from Brazil): São Paulo: forty one workers and two gynes from Salesópolis (Same locality of the Holotype, but collected in different dates and by different collectors); 33 workers and 2 gynes deposited in MZSP, one worker deposited in, one worker deposited in , one worker deposited in , one worker deposited in , one worker deposited in , one worker deposited in , one worker deposited in , one worker deposited in.

Etymology
We are pleased to dedicate this species to our friend and colleague, Rogério Rosa da Silva, the most efficient collector in our team.

References based on Global Ant Biodiversity Informatics

 * Albuquerque, N.L. and C.R.F. Brandao. 2009. A revision of the Neotropical Solenopsidini ant genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae): 2. Final. Key for species and revision of the Rastratus species-group. Papéis Avulsos de Zoologia (São Paulo) 49(23): 289-309.
 * Silva R.R., and C. R. F. Brandao. 2014. Ecosystem-Wide Morphological Structure of Leaf-Litter Ant Communities along a Tropical Latitudinal Gradient. PLoSONE 9(3): e93049. doi:10.1371/journal.pone.0093049
 * Ulyssea M. A., C. R. F. Brandao. 2013. Catalogue of Dacetini and Solenopsidini ant type specimens (Hymenoptera, Formicidae, Myrmicinae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papies Avulsos de Zoologia 53(14): 187-209.