Leptogenys lohahela

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

Leptogenys lohahela casent0001203 p 1 high.jpg

Leptogenys lohahela casent0001203 d 1 high.jpg

Specimen Labels

Leptogenys lohahela is limited to the rainforest of the PN Andohahela in southern Madagascar. It has been collected from leaf litter sampling and pitfall traps. The species forages on the forest floor and nests in rotting tree stumps.

Identification

A member of the saussurei species group. Rakotonirina and Fisher (2014) - Worker. Mandible short and robust, capable of closing tightly against clypeus; anterior clypeal margin medially projecting into triangular lobe; clypeus with sharp edge or lamella. Eye large, diameter markedly greater than maximum width of antennal scape. Dorsum of head and mesosoma noticeably sculptured; with mesosoma in dorsal view, metanotal groove distinctly visible. In dorsal view, posterior margin of petiolar node straight, not medially excised; in profile posterolateral margin of petiolar node with small, sharp tooth.

Leptogenys lohahela can be confused with Leptogenys saussurei and Leptogenys acutirostris with respect to the presence of metanotal groove, but the latter species are larger in size, the posterior margin of the petiolar node, in dorsal view, is medially emarginated for L. sausurei, and the posterolateral margin of petiolar node, in profile, is with a blunt angle, not a small sharp tooth for L. acutirostris.

Keys including this Species

Distribution

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

Nomenclature

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

  • lohahela. Leptogenys lohahela Rakotonirina & Fisher, 2014: 121, figs. 1B, 34A, 36A, 139, 146 (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

(7 specimens). HW: 1.49–1.73, HL: 2.02–2.29, CI: 72–75, SL: 1.98–2.26, SI: 128–137, PW: 1.30–1.42, WL: 3.07–3.38, PNH: 1.13–1.34, PNL: 0.93–1.19, PNW: 0.92–1.06, DNI: 88–108, LNI: 112–122.

Head more or less rectangular, width not increasing from level of eyes to the front, but slightly decreasing behind level of eye toward posterior border of head. Median lobe of clypeus triangular and prominent, without anterior teeth on each side of median carina; lateral margin not interrupted and sharp. Metanotal groove visible with mesosoma viewed dorsally; in profile, mesopleural sulcus indistinct, but upper portion at level of metathoracic spiracle with wide, shallow impression. In dorsal view, petiolar node longer than broad, posterior margin straight and not medially excised. With head in profile, anterolateral portion from level of eye reticulate-rugose; in full-face view, the dorsum with dense punctures which become shallower and more scattered near posterior cephalic margin. Mandible finely striate, interspersed with piligerous punctures. Dorsum of pronotum distinctly with larger and denser punctures compared to the rest of dorsum of mesosoma. In dorsal view, petiolar node covered with smaller and sparser punctures; in profile, upper half of sides of node densely punctate, superimposed with faint rugulae.

Holotype Specimen Labels

Type Material

Holotype worker: Madagascar, Toliara, PN Andohahela, Col de Sedro, 3.8 km 113° ESE Mahamavo, 37.6 km 341° NNW Tolagnaro, -24.7639, 46.7517, 900 m, montane rainforest, ground forager, 21–25 Jan 2002 (Fisher, Griswold Arthropod Team) collection code: BLF05234, specimen code: CASENT0001203 (California Academy of Sciences). Paratypes: 2 workers with same data as holotype but with specimen codes: CASENT0001198, CASENT0247210 (CASC, The Natural History Museum).

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.