Leptogenys australis

Specimens from Cerro Animas, Uruguay were found under a stone.

Identification
Key to Leptogenys of the New World

Lattke (2011) - Eye relatively flat, laterally situated at mid-length of lateral cephalic margin; mesonotum with curved anterior and posterior margins; metanotal groove scrobiculate, propodeal declivity transversely striate.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Uruguay.

Castes
Queen, male. Unknown.

Nomenclature

 *  australis. Lobopelta australis Emery, 1888e: 693 (w.) ARGENTINA. Combination in Leptogenys (Lobopelta): Emery, 1911d: 105. Senior synonym of hanseni: Lattke, 2011: 227.
 * hanseni. Leptogenys (Lobopelta) hanseni Borgmeier, 1930: 31, pl. 4, figs. 16, 23, 24, 27, 28 (w.q.) BRAZIL. Junior synonym of australis: Lattke, 2011: 227.

Lattke (2011) - In the MCSN collection a single worker, obliquely glued to a carton, was examined. It is apparently the only specimen examined by Emery and is consequently considered the holotype even though Emery did not designate it as such. One of the measured specimens lacks both antennae. The syntypes of L. hanseni in MZSP correspond to L. australis. L. hanseni has the propodeal spiracle slightly ovoid, and the mesonotum a bit more ovoid (not as transverse) than in L. australis but such differences exist amongst conspecifics in other Leptogenys. Borgmeier (1930) did not consider L. australis when discussing other Leptogenys close to L. hanseni. Another syntype of L. hanseni deposited in the IBSP was also examined. The specimen is cleaner than the  specimens.

Worker
Lattke (2011) - Metrics (n = 2) : HL 0.94 – 0.94; HW 0.58 – 0.61; ML 0.40 – 0.46; EL 0.10 – 0.13; SL 0.03 – 0.78; PW 0.53 – 0.56; WL 1.32 – 1.37; PH 0.53 – 0.53; PL 0.53 – 0.56; DPW 0.38–0.38 mm. CI 0.62–0.65; MI 0.70–0.75; OI 0.17 – 0.21; SI 0.04 – 1.35; LPI 0.95 – 1.00; DPI 0.68 – 0.71.

Head rectangular in full-face view, lateral margins parallel, straight; posterior margin straight, vertexal carina visible; head width greatest behind eyes; eye relatively flat, lens of each ommatidium fusing with each other, laterally situated at mid-length of lateral cephalic margin; median clypeal process abruptly protrudes anterad, about as long as broad, basally slightly converging then at mid-length tapering to pointed tip. Front of head smooth and shining. Mandible with sinuate basal margin, convex basad and concave apicad; apical half of convexity with row of stiff hairs; chewing margin brief, edentate with blunt apical tooth; dorsum smooth and shining, not expanded apicad into triangular shape. Scape surpasses posterior cephalic border by 2 apical widths, smooth and shining, with abundant semi-erect hairs, funicular segments I–III about same size, apical widths of each segment more than half their respective lengths.

Mesosoma with broadly convex promesonotal margin in lateral view; metanotal groove shallow but distinctly impressed, scrobiculate; dorsal propodeal margin mostly weakly convex to straight, convex towards declivity, tooth bluntly triangular. Mesosoma mostly mostly smooth and shining, some striae present on mesopleuron, and ventral metapleuron. Meso-metapleural suture well impressed, scrobiculate; anteroventral mesopleural carina well developed dorsally, becoming progressively narrower ventrad. Propodeal spiracle rounded to oval, posteriorly facing. Mesonotal dorsal surface convex, wider than long in dorsal view. Propodeal declivity with transverse striae on anterior half, and smooth posterad of teeth. No metapleural-propodeal suture visible.

Petiole in lateral view with vertical anterior and posterior margins, posterior margin about half the height of posterior margin; dorsal margin highest posterad, about as long as posterior margin, with slope most of distance of posterior convexity. Node smooth and shining, posterior face flat and with sharp curves separating it from sides. Node in dorsal view shaped as elongate trapezoid, anterior margin broadly convex, more than two-thirds the width of posterior margin, sides almost straight. Anterior postpetiolar margin vertical. Body light brown, legs, antenna, mandibles ferruginous. Gaster smooth and shining, constriction between abdominal segments III and IV well marked. Scant pilosity observed on examined specimens.

Type Material
Lattke (2011):

Holotype worker: Argentina, La Plata (C. Spegazzini) (MCSN) [examined].

Leptogenys (Lobopelta) hanseni. Syntype workers: Brazil, Rio Grande do Sul, Parecy Novo, 7.x.1927, under a stone (A. Hansen) (MZSP, IBSP) [examined].

Additional References

 * Lattke, J.E. 2011. Revision of the New World species of the genus Leptogenys Roger (Insecta: Hymenoptera: Formicidae: Ponerinae). Arthropod Systematics & Phylogeny 69:127-264.