Oxyepoecus quadratus, Albuquerque, Nicolas Lavor De & Brandão, Carlos Roberto F., 2004

Albuquerque, Nicolas Lavor De & Brandão, Carlos Roberto F., 2004, A Revision Of The Neotropical Solenopsidini Ant Genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 1. The Vezenyii Species- Group, Papéis Avulsos de Zoologia 44 (4), pp. 55-80 : 73-75

Oxyepoecus quadratus sp. nov.

( Figs. 6 a-c)

Oxyepoecus quadratus Albuquerque and Brandão. Holotype worker, Ecuador: Cuyabeno [0°16’S, 75°53’W], 27.i.1994, J.P. Caldwell [col.], deposited in MZSP.

Paratype: worker. Peru: Panguana : Huanaca [9°37’S, 74°56’W], 26.xi.1983, M. Verhaagh [col.], deposited in MZSP .

Etymology: From the shape of the superior face of the petiolar node clearly subquadrate.

Worker: Holotype and paratype within brackets t.l.= 2.32 (2.37); h.l.= 0.45 (0.46); h.w.= 0.46 (0.47); s.l.= 0.32 (0.36); m.l.e.= 0.09 (0.12); m.w.pr.= 0.32 (0.36); a.l.= 0.63 (0.68); h.f.l.= 0.38 (0.40); m.w.p.= 0.20 (0.24); m.w.pp.= 0. 23 (0.26); c.i. 97 (96). Color chestnut brown; mandibles, antennae, legs yellowish; and gaster fuscus, almost black. Integument smooth and shining, with the following exceptions: frontal carinae longitudinally costulate, prolonged posteriorly, reaching the level of the superior orbit of the compound eyes; genae with well marked longitudinal rugae that reach superiorly the inferior orbit of compound eyes and inferiorly the mandibular insertion; postero-lateral limit of disc of the pronotum, sides and anterior third of mesonotum, and metapleuron with longitudinal well marked costulae, of which one is prolonged posteriorly and curved over the bulla of the metapleural gland region, but specially on disc of pronotum and anterior third of mesonotum the costulae can be less marked; dorsal face of the propodeum with some well marked and curved costulae, 7-10 well formed, with ends over the sides of the propodeum; declivous face with two well formed costulae, the superior reaching the costulae of metapleuron and communicating with them; sides of the petiole with costulae in different orientations, but generally the penducle has many longitudinal costulae and the node has many transverse; posterior and dorsal surfaces of postpetiole with several small but well formed costulae. Hairs abundant, decumbent on cephalic disc, the majority turned to head median stripe; on cephalic border long, suberect without a regular orientation; long, suberect and relatively curved on pronotum, mesonotum with some long and erect; and metapleuron dorsum scarcely hairy, petiole node with some suberect and subdecumbent hairs; there are some decumbent on the postpetiole.

Head as shown in Fig. 6a (f.f.v.). Mandibles elongated, with a broad and relatively shallow diastema between the basal and subbasal tooth, also between the subbasal tooth and the other teeth. Anterior teeth of clypeus with small, blunt and lobe-like lateral denticles. Frontal carinae relatively short, subparallel, with a posterior moderate divergence and with a small constriction posteriorly, reaching the level of the straight line that passes through the inferior orbit of the compound eyes, the maximum width between their outer edges less than one third of the head width. Compound eyes small, with about 5-7 facets r.g.d.; total number of ommatidia about 16-18. Antennal scape failing to reach the occipital corner by a distance approximately equal to the maximum thickness of the scape. Funicular segment I as long as II-VI combined, segments II-VII distinctly broader than long, VIII and IX as long as broad.

Mesosoma as shown in Fig. 6b . Promesonotum convex, marginate in front and laterally; shoulders marked, but without a defined angle. Metanotal groove not at all impressed (p.v.). Dorsal face of the propodeum posteriorly with two acute and prominent spines. Declivous face laterally marginate and weakly carinate. Propodeal lobes irregularly rounded.

Petiole in dorsal view as shown in Figs. 6 b-c, node high and subquadrate at superior face (p.v.), antero-posteriorly compressed in a scale-like fashion, almost as broad as postpetiole; subpetiolar process as a sagital and undulate keel anteriorly ending in a prominent plate-shaped tooth. The postpetiole very broad, in a scalelike fashion, the level of the superior face lower than the petiole node is high; subpostpetiolar process small, almost imperceptible, extremely shallow.

Gyne unknown.

Male unknown.

Diagnosis, distribution and comments

The exclusive character of the workers of O. quadratus is the subquadrate petiolar node (p.v.), but also the distribution of marked costulae on head and mesosoma are important. The distribution of O. quadratus is represented by two localities in western Amazonian region, in Peru and Ecuador (fig. 8).

Examined material: Ecuador: Cuyabeno , 27.i.1994, J.P. Caldwell [col.] [0°16’S, 75°53’W] (1 Ψ paratype, coated with gold for SEM) ; Peru: Panguana : Huanaca, Yuyapidis river, 26.xi.1983, M Verhaagh [col.], inundation forest, collected using pitfall trap [9°37’S, 74°56’W] (Ψ holotype) .

Figures

FIGURE 6. Scanning electron micrograph of the workers of O. quadratus; a) head in full-face view; b) mesosoma in profile view; c) petiole in dorsal view.