Leptogenys diana

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Leptogenys diana
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species group: truncatirostris
Species complex: truncatirostris
Species: L. diana
Binomial name
Leptogenys diana
Rakotonirina & Fisher, 2014

Leptogenys diana casent0162488 p 1 high.jpg

Leptogenys diana casent0162488 d 1 high.jpg

Specimen Labels

Leptogenys diana has been found foraging on the ground and nesting under rocks and in rotten logs. Though its hunting habits are not known, the shape of the mandible with the strange, soft striate outer surface, and the limited anterior clypeal lamella, no doubt have interesting behavioral implications.

Identification

A member of the truncatirostris complex of the truncatirostris species group. Rakotonirina and Fisher (2014) - Worker. Clypeus broadly rounded, without projecting anteromedian lobe; median clypeal carina lacking; lateral portion joins anterior margin of clypeus in a convex line. In profile, mandible strongly bent downward;in full-face view, blades clearly broadened and flattened at about mid-length, with longitudinal and fine striation; inner margin evenly curved from distal half to apical sharp tooth; in profile, third abdominal segment microreticulate (coriaceous) with scattered punctures; dorsum of mesosoma, petiolar node, and gaster without pubescence.

This species can be confused with Leptogenys truncatirostris, but the latter is characterized by a broad anterior margin of the clypeus with angulate lateral margins; the abundant pubescence on the dorsum of the mesosoma, petiolar node and gaster; and dense reticulate punctures on the third abdominal segment.

Keys including this Species

Distribution

Leptogenys diana is restricted to the dry forest of the Montagne des Français and RS Ambre near the northern tip of the island, in two disjunct populations.

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The Leptogenys genus page has more details about the general biology of ants in this genus. The following synopsis provided by Rakotonirina and Fisher (2014) offers an overview of the Malagasy Leptogenys: Recent surveys of arthropods in the Malagasy region uncovered a wealth of new species and showed that Leptogenys is one of the dominant ponerine ants widely distributed across all types of forest habitats. Workers are usually found foraging on the forest floor or in the leaf litter and only rarely on vegetation. They nest terrestrially under the soil, rocks, logs, or rootmat ground layers and in rotten logs, branches, in rotting bamboo, and rotten tree stumps. Most of the Malagasy species are endemic to Madagascar. In all Malagasy species, winged queens are absent, which limits their ability to disperse across the complex topography and various ecological barriers in the region. In the absence of alate queens, reproduction of Leptogenys in the region may be by fission, which enhances population viscosity and may result in important morphological variation across a species' geographic range. Though queens do not fly, males of Leptogenys are alate and are one of the most frequently collected ant genera in Malaise traps throughout Madagascar. Leptogenys exhibits a wide range of phenotypic diversity segregated both among spatially isolated habitats and along continuous environmental gradients.

Castes

Worker

Nomenclature

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

  • diana. Leptogenys diana Rakotonirina & Fisher, 2014: 145, figs. 12A, 162, 171 (w.) MADAGASCAR.

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

Description

Worker

(5 specimens). HW: 1.66–1.77, HL: 1.81–1.89, CI: 91–43, SL: 1.79–1.85, SI: 105–109, PW: 1.13–1.20, WL: 2.89–3.15, PNH: 0.96–1.05, PNL: 0.87–0.95, PNW: 0.87–0.91, DNI: 95–100, LNI: 108–117.

Head subquadrate, not diverging anteriorly; sides nearly straight; posterior margin slightly concave. Eye large, occupying one-third to one-fourth the length of lateral cephalic margin and extending beyond line of sides of head. Antennal scape relatively short, roughly one-fifth of its length surpassing posterior cephalic margin. In profile, mandible strongly bent downward; in full-face view blade increasing in width at distal half, then gradually, narrowly arched toward apex; small preapical tooth may be present. Anterior clypeal margin meets lateral portions in rounded angle, anterior lamella limited to anteromedian portion, not broadly covering the clypeus; medial longitudinal carina absent. Antennal scape relatively short, roughly one-fifth of apical portion surpassing posterior cephalic margin. With mesosoma in dorsal view, metanotal groove cross-ribbed; in lateral view, posterolateral border of propodeum smooth, without toothlike lobe. Outer surface of mandible from distal half to apex densely and finely striate, softcuticleand golden in color. Dorsum of head, mesosoma and petiolar node densely reticulate-punctulate. Third abdominal tergite generally microreticulate or coriaceous, with scattered punctures. Dorsum of mesosoma, petiolar node, and gaster covered with erect hairs; pubescence absent. Color black, with brown to light brown apical portion of appendages and tip of gaster.

Type Material

Holotype worker: Madagascar, Antsiranana, RS Ambre, Sakaramy, -12.4423, 49.2288, 402 m, tropical dry forest, ex rotten log, 15 May 2011 (B.L. Fisher et al.) collection code: BLF27337, CASENT0261104 (California Academy of Sciences). Paratype worker: with same data as holotype but specimen coded: CASENT0261074 (CASC).

References

  • Rakotonirina, J.C. & Fisher, B.L. 2014. Revision of the Malagasy ponerine ants of the genus Leptogenys Roger (Hymenoptera: Formicidae). Zootaxa 3836, 1-163.