Oxyepoecus vezenyii (Forel)

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 : 75-77

Oxyepoecus vezenyii (Forel)

( Figs. 7 a-c)

Monomorium (Martia) vezenyii Forel, 1907:20-21 , (Ψ Paraguay). Borgmeier, 1928 b:65 (key).

Martia vezenyii: Kusnezov, 1952:720 , 722

Oxyepoecus vezenyii: Ettershank, 1966:145 , Figs. 114-119 (worker). Kempf, 1969:277-278 (♀ Brasil). Kempf 1972:173. Kempf, 1974:505.

Worker: t.l.= 2.40-3.00; h.l.= 0.57-0.67; h.w.= 0.47-0.55; s.l.= 0.36-0.41; m.l.e.= 0.08-0.09; m.w.pr.= 0.36-0.44; a.l.= 0.68-0.79; h.f.l.= 0.39-0.47; m.w.p.= 0.23-0.31; m.w.pp.= 0.27-0.35; c.i. 79-84. Color light ferruginous; gaster somewhat infuscate. Integument smooth and shining, with the following exceptions: frontal carinae longitudinally costulate, prolonged caudad and obliquely laterad, surpassing the level of the superior margins of the compound eyes where they become faint to vestigial; genae with longitudinal costulae that reach the inferior margin of the compound eyes and the inferior margin of clypeus, close to the mandibular insertion; postero-lateral corner of the dorsal disc of pronotum, with some piligerous punctuations longitudinally oriented; sides of the pronotum smooth and shining; postero-inferior region of the anepisternum, katepisternum, sides of the propodeum and all metapleuron longitudinally costulate, which vary in their degree of distinctness, weak to conspicuous; dorsal face of the propodeum with 10-13 costulae, 8 strong, the others less distinct; sides of the petiolar node with a few widely spaced horizontal longitudinal costulae; sides and posterior surface of postpetiole with several rows of indistinct to well-expressed costulae. Hairs moderately abundant, short to long, suberect on head, dorsum of mesosoma, petiole, postpetiole, and on gaster; subdecumbent on head; most hairs inclined mesad dorsally on discs, forwards on the sides; decumbent on the mandibles; gaster without ground hairs.

Head (f.f.v.) with the mandibles relatively elongated, and with a broad and relatively shallow diastema between the basal and subbasal tooth (fig. 7a). Anterior teeth of clypeus divergent with lateral, blunt, lobelike, denticles. Frontal carinae with their superior ends divergent and relatively close, the maximum width between their outer edges always less than one third of the head width. Compound eyes relatively small, with about 6-7 facets r.g.d., which is less than the distance between the inferior orbit and the mandibular insertion: total number of ommatidia circa 20. 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-V combined, segments II-VII distinctly broader than long, VIII and IX as long as broad.

Mesosoma as shown in Figs. 7b (p.v.) with the shoulders shallowly marked, sides of pronotum submarginate. Metanotal groove shallowly to not at all impressed (p.v.), metanotal suture indistinct. Dorsal face of the propodeum immarginate on sides, posteriorly with two pointed, obliquely oriented teeth. Declivous face laterally marginate and weakly carinate.

Petiole pedunculate, node antero-posteriorly compressed and laterally expanded in a scalelike fashion ( Figs. 7 b-c), almost as broad as postpetiole (d.v.); subpetiolar process anteriorly blunt and somewhat plate-like (p.v.). The postpetiole unusually broadened due to the drawn out lateral bulky lobes. Subpostpetiolar process with two subparallel crests, of approximately equal size.

Gyne (ergatomorphic): t.l.= 3.10; h.l.= 0.64; h.w.= 0.53; s.l.= 0.43; m.l.e.= 0.11; m.w.pr.= 0.43; a.l.= 0.84; h.f.l.= 0.46; m.w.p.= 0.30; m.w.pp.= 0.35; c.i. 82. Resembling worker with the modifications appropriate to the caste. Eyes surprisingly small, as in workers, with less than 30 ommatidia. Ocelli minute, their diameter less than the minimum thickness of the antennal scape. Mesosoma (p.v.) with blunt marked shoulders; pronotum not declivous in the middle. Mesonotum (scutum and scutellum) relatively small, their combined length approximately equal to one half of mesosoma length; scutum smooth and shining with strong piligerous punctulae; scutellum entirely smooth. Dorsal face of the propodeum transversely costate, with 8-10 costae, which continue downwards and obliquely forwards on the sides. Mesopleuron smooth and shining. Propodeal teeth short but pointed. Petiole and postpetiole as in workers.

Diagnosis, distribution and comments

Workers of O. vezenyii are diagnosed by a combination of characters: the elongate mandible; the relatively small eyes with circa 20 ommatidia, and the pattern of microsculpture between the frontal carinae. The distribution of O. vezenyii , as shown in fig. 9, seems discontinuous, with ten localities at south, southeast, mid and western-center, and north Brazil, It includes different Brazilian ecosystems and biomes, but the absence in intermediate localities could be an effect of the application of techniques inappropriate in these gaps.

The gyne runs near those of O. bruchi in Kempf ’s (1974) key, however it is differentiated by the pronotum, which is not declivous in the middle, and by the relatively small mesonotum.

Examined material: Brasil: Goiás: 20 Km W of Chapadão do Céu, Parque Nacional das Emas, 27-30.v.1997, Brandon Bestelmeyer [col.] # CE1-6, CBI-9, CB1-9 , CL2-5, [18°07’S 52°53’W] (4 Ψ) ; Mato Grosso: Cuiabá, 5 Km of Av [enue] Perimetral , Cerrado with stream, 19.ii.1985, J.C. Trager [col.] # 0642 [15°36’S 56°06’W] (2 Ψ) ; Rio Grande do Sul: Erechim, viii.1956, F. Plaumann [col.] [27°38’S 52°16’W]; [Itatí], CPCN Pró-Mata , 18.iii.1997, J. Ketterl [col.] 29°30’S 50°10’W , Araucaria Forest , ~ 900 m, Soil Litter Sifting (Winkler) Wn 4 (1 Ψ) ; Santa Catarina: Ibicaré , ix.1960, F. Plaumann [col.] (WWK) # 8103 [27°06’S 51°23’W] (10 Ψ); Luzerna, i.1963, Fr. Libório Schmitt [col.] (2 Ψ); Nova Teutônia, viii.1952, x.1953, vi.1959, vii.1959, vi.1960, F. Plaumann [col.] # 8089 (Borgm. Coll.), (WWK) # 8301, 8177, 8163, 8326 [27°02’S 52°24’W] (22 Ψ e 1 ♀) ; Seara, v-xii.1998, Rogério R. Silva col. 24°07’S 52°18’W (1 Ψ) ; São Paulo: Salesópolis , v.1971, W.L. Brown Jr. [col.] [23°39’S 45°53’W] (1 Ψ) ; Tocantins: Palmeirante, Mata Ciliar / Cerradão , 10-15.xii.2001, Albuquerque. N.L. & Silva R. R. Cols 07°52’S 47°57’W (7 Ψ).

Figures

FIGURE 7. Scanning electron micrograph of the workers of O. vezenyii (Forel, 1907); a) head in full-face view; b) mesosoma in profile view; c) petiole in dorsal view.