Oxyepoecus Rastratus

Albuquerque, N. L. de & Brandão, C. R. F., 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., Papeis Avulsos do Departamento de Zoologia 49, pp. 289-309 : 293

Rastratus Group - diagnosis

The species included in the Rastratus group are characterized by the cephalic dorsum entirely costulate or, in the case the sculpture covers only partially the head dorsum, the area between the frontal carinae is always sculptured, while in species of the Vezenyii group this area is always smooth. To name the species group we use the oldest published specific name.

description of Rastratus group Oxyepoecus workers

Color: varies from reddish-yellow to almost black; mandible, antennal club and scape, and yellowish legs are usually lighter than other body parts. The integument can be almost totally smooth and shining when observed under the stereomicroscope; when the integument presents microsculpture it appears as short or long, straight, curved or undulate costulae (sometimes set in a net, called then irregularly reticulate), straight or curved rugae, striae (thinner than rugae), and piligerous punctuations. The longitudinal costulae between the frontal carinae, when present, surpass the level of a virtual line that crosses the superior margins of the compound eyes (referred from now on as the level of the superior margins of the compound eyes; we adopt the same terminology for the inferior margins), and can reach posteriorly the vertex margin; laterally the costulae can reach the margin above the compound eyes. The hairs can appear as background pubescence or individually, decumbent to erect; generally the antennal club presents a fine pubescence, while the coxae, tarsomeres and gaster are smooth and free of pubescence. The head vertexal margin in frontal view can be straight, gently convex, or present a small central concavity. Mandible subtriangular, ranging from elongate to short. Posterior region of the frontal carinae, posterior to the antennal sockets, subparallel or convex, externally with a posterior constriction(f.f.v.); the maximum width between their outer edges (always taken in the midlength of the carinae) ranges from one fifth to one third of the head width. The compound eyes have as few as 3 facets r.g.d. and as many as 10 r.g.d. The total number of ommatidia ranges from 5-6 to 30; the greatest diameter can be equal or shorter than the virtual straight line linking the anterior margin of the compound eye and the mandibular insertion, (oculomalar distance). The anterodorsal corner of the pronotum (called hereafter shoulders) can be gently marked, as an angle between the superior and the lateral surfaces, or rounded. The metanotal groove is visible or not at all perceptible. The basal face of the propodeum is smooth or presents transversal costulae. The declivous face of the propodeum is smooth or presents some oblique rugae or striae, and may present a margin separating the posterior and lateral faces. The peduncle of the petiole can be relatively long; in dorsal view, the petiolar node width can be almost the double of the peduncle width. The postpetiole can be as high as the petiolar node (p.v.), and its width can be equal to or greater than that of the petiolar node (d.v.).

The Rastratus group includes the following species:

• Oxyepoecus daguerrei (Santschi, 1933);

• Oxyepoecus mandibularis (Emery, 1913);

• Oxyepoecus myops n. sp.;

• Oxyepoecus plaumanni Kempf , 1974;

• Oxyepoecus rastratus (Mayr, 1887);

• Oxyepoecus reticulatus Kempf , 1974;

• Oxyepoecus rosai n. sp.