Oxyepoecus vivax

This species is only known from a holotype queen specimen.

Identification
The diagnostic characters of O. vivax gynes in relation to the other species in the Vezenyii group are the elongate mandibles, the blunt clypeal denticles and the relatively scarcely laterad expanded postpetiole (Albuquerque and Brandão 2004).

Distribution
The lone holotype specimen was found in Minas Gerais State, Brasil.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Biology
Nothing is known about the biology of this species.

Castes
Only known from the queen.

Nomenclature

 *  vivax. Oxyepoecus vivax Kempf, 1974b: 508, figs. 31-33, 38, 39 (q.) BRAZIL. Albuquerque & Brandão, 2004: 77 (q.).

The unusually elongate and linear mandibles place vivax in the vicinity of Oxyepoecus inquilinus (the female of which is still unknown), differing, however, in the blunt clypeal armature, the entirely sculptured frons, the globose, not scalelike petiolar node, the relatively little expanded postpetiole.

The relatively large size is shared with Oxyepoecus mandibularis (the latter likewise known only in the worker caste, and not seen during this study), which has short, triangular mandibles with a deep cleft between basal and subbasal tooth on the chewing border, and the cephalic dorsum more heavily and extensively sculptured.

From the already known queens in genus Oxyepoecus, vivax is readily separated by its much larger size, the long, linear mandibles, the irregular sculpture on basal face of propodeum.

Queen
(holotype). Total length 3.8 mm; head length 0.75 mm; head width 0.67 mm; scape length 0.58 mm; maximum diameter of eyes 0.29 mm; Weber's length of thorax 1.09 mm; maximum width of pronotum 0.61 mm; hind femur length 0.73 mm; fore wing length 2.4 mm; hind wing length 2.0 mm; petiole width 0.27 mm; postpetiole width 0.32 mm; cephalic index 89. Color reddish brown; vertex, occiput, posterior portion of sides of head, and gaster somewhat infuscated; mandibles, legs except coxae, and antennae yellowish brown. Wings slightly infumated, veins light brown. Integument smooth and shining with the following exceptions: cheeks and lateral portions of clypeus finely longitudinally costulate; frontal carinae and frons finely longitudinally costulate, the posterior portions rather indistinct, not reaching laterally the eyes nor posteriorly the ocelli; occiput with transverse costulae; dorsum of pronotum feebly and obliquely costulate; paraptera and scutellum regularly longitudinally costulate; basal face of propodeum with oblique, asymetrically disposed rugulae or costae; mesopleura, metapleura and sides of propodeum with patches of costulate sculpture; sides and posterior surface of petiolar and postpetiolar node horizontally, respectively transversely costulate. Hairs abundant, standing on dorsum of head and thorax, oblique on petiole and gaster; shorter, inclined hairs on dorsum of head, sides of head, mandibles, antennae and legs.

Head. Mandibles elongate, sublinear, the basal border longer than the chewing border with which it scarcely forms an angle; a broad but shallow diastema between the small basal and subbasal tooth. Median apron of clypeus protruding, with the usual longitudinal, anteriorly diverging carinae, but the anterior teeth are blunt and scarcely prominent, and the lateral dentides minute and inconspicuous. Frontal carinae, except the anterior curvature, absolutely straight and parallel, the distance between their outer edges slightly less than one third of the head width, as measured behind the eyes. Frontal area smooth, impressed, ill-delimited. Eyes huge, prominent, with several hundred ommatidia, oval in outline. Ocelli small. Antennal scapes nearly reaching the narrowly rounded occipital corner when laid back over the head as much as possible. Funicular segments I, VIII, IX and X much longer than broad, II-VI somewhat broader than long, VII about as long as broad. Occiput in full-face view slightly excavated.

Thorax. Pronotum entirely declivous in the middle, the sides submarginate, the shoulders practically rounded, scarcely marked. Propodeal armature consisting of short yet pointed spines; in dorsal view their length is less than half the distance between the inner side of their bases. Declivous face of propodeum slightly excavate and laterally carinate. Wings: note the variation in the same individual, where the discoidal cell is reduced to a small solid rectangle in the left fore wing, while it is normal in the right fore wing. Hind wing with 6 hamuli.

Petiole and postpetiole. Petiole pedunculate, subpetiolar tooth small, node globose, in dorsal view only slightly shorter than broad, not expanded laterad nor antero-posteriorly compressed: postpetiole likewise little compressed antero-posteriorly and very little expanded laterad, not conspicuously broader than petiolar node; anterior subpostpetiolar process very prominent, but not bidentate. Gaster not excised nor truncate in front.

Type Material
Kempf (1974) - A single female (holotype, WWK n. 8836), collected by Dr. C. A. C. Seabra & Lt.-Cel. Moacyr Alvarenga at Pedra Azul, altitude 800 m, XI-1972, in the northeast of the State of Minas Gerais, Brazil.

Additional References

 * Albuquerque, N. L. d. and C. R. F. Brandão. 2004. A revision of the Neotropical Solenopsidini ant genus Oxyepoecus Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 1. The Vezenyii species-group. Papéis Avulsos de Zoologia (São Paulo). 44:55-80. DOI: 10.1590/S0031-10492004000400001