Leptogenys manja

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

Leptogenys manja casent0068233 p 1 high.jpg

Leptogenys manja casent0068233 d 1 high.jpg

Specimen Labels

Leptogenys manja occurs in lowland rainforests of Ambodiriana Reserve at 125 m and the RS Manombo at 30 m. In lowland rainforests, workers of L. manja forage through the leaf litter and on lower vegetation.

Identification

A member of the imerinensis complex of the incisa species group. Rakotonirina and Fisher (2014) - Worker. Peg-like setae present on the anteromedial clypeal lobe, projecting anteriorly from above the much narrower semi-translucent lamella; width of lamella less than the minimum diameter of antennal scape; scape relatively long (SI 136–140), more than apical third portion extending beyond posterior cephalic margin. Mandible generally smooth apart from short striation and sparse punctures; blade narrow and not strongly curved at the base, inner margin concave. Dorsum of mesosoma composed of three segments.

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.

  • manja. Leptogenys manja Rakotonirina & Fisher, 2014: 90, figs. 40B, 48A, 50B, 51B, 103, 119 (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

(2 specimens). HW: 1.57–1.59, HL: 1.85–1.86, CI: 85, SL: 2.16–2.20, SI: 136–140, PW: 1.23–1.29, WL: 3.32–3.47, PNH: 0.92–0.96, PNL: 1.04–1.06, PNW: 0.87–0.90, DNI: 82–86, LNI: 87–92.

Head fairly long, much wider at front than behind. Eye strongly protruding from head surface. Antennal scape distinctly long, more than one-third of its length extending beyond posterior cephalic margin. Anterior margin of clypeus medially broadly angulate with a blunt apex; semi-translucent membrane on lateral and anteromedian margin of clypeus narrower than minimum diameter of scape. Mandible long and slender, not strongly curved at base; inner margin concave, apical tooth obtuse and not reaching anterior margin of clypeus when mandibles close. Hypostomal teeth short and not visible when head in full-face view. In dorsal view, mesosoma characterized by three visible segments; metanotal groove impressed; in lateral view, dorsum of propodeum slightly convex and relatively long and low, rounding to short declivitous surface. With petiole in profile, node roughly elongate, anterior face vertical and posterior margin inclined anteriorly and rounding with convex dorsal margin. Strong constriction present between third and fourth abdominal segments. Mandible smooth, with effaced longitudinal striation and sparse punctures. Head and mesosoma densely reticulate-rugose dorsally; propodeal declivity transversely rugose. Node of petiole laterally reticulate-rugose; the dorsum mostly finely microreticulate, interspersed with widely spaced, large punctures. Standing hairs and pubescence present on dorsum of body. Body black, with ferruginous-brown apex of appendages and tip of gaster.

Type Material

Holotype worker: Madagascar, Toamasina: Réserve Ambodiriana, 4.8 km 306° Manompana, along Manompana River, -16.6723, 49.7012, 125 m, rainforest, ground forager, 19 Nov 2005 (B.L. Fisher et al.), collection code: BLF12837, specimen code: CASENT0068233 (California Academy of Sciences).

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.