Leptogenys australis

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Leptogenys australis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species: L. australis
Binomial name
Leptogenys australis
(Emery, 1888)

Leptogenys australis casent0178834 profile 1.jpg

Leptogenys australis casent0178834 dorsal 1.jpg

Specimen labels

Synonyms

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

Identification

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.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (type locality), Brazil, Uruguay.


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The biology of Leptogenys australis is poorly known.

The Leptogenys genus page has more details about the general biology of ants in this genus, some of which is summarized in what follows. New World species have relatively small ranges, generally occur in humid forests and prey on isopods. Colonies may occur in high densities on a local scale, with up to 5 or 6 species present. Nest size tends to be small with just 20 or 30 individuals in a mature colony. Nests of most species may be found in rotten wood on the ground, usually within cavities in logs or large branches, and also beneath bark. Wood-soil and rock-soil interfaces are another common nesting location, as well as rock crevices, and a few species may nest directly in the soil. Reproduction is most commonly via ergatoid females and, in many species, may include egg-laying workers.

Castes

Queen, male. Unknown.

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • 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.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

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 Instituto Butantan specimen is cleaner than the Museu de Zoologia da Universidade de Sao Paulo specimens.

Description

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].

References