Leptogenys manongarivo

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search
Leptogenys manongarivo
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species group: attenuata
Species: L. manongarivo
Binomial name
Leptogenys manongarivo
Rakotonirina & Fisher, 2014

Leptogenys manongarivo casent0196540 p 1 high.jpg

Leptogenys manongarivo casent0196540 d 1 high.jpg

Specimen Labels

The only specimens are a few workers that were found foraging on the ground in a single collecting event, suggesting that the species is locally endemic.

Identification

A member of the attenuata species group. Rakotonirina and Fisher (2014) - Worker. Length of third antennal segment less than twice the length of the second; eye breaking outline of sides of head; basal half of mandible finely longitudinally striate; finely microreticulate, interspersed with punctulae; side of propodeum smooth; posterodorsal angle of node projecting posteriorly and overhanging its posterior margin.

Leptogenys manongarivo is similar to Leptogenys grandidieri with respect to the shape of the petiolar node, whose posterodorsal margin feebly overhangs the posterolateral margin, but L. manongarivo is easily distinguished by the smooth surface of the sides of its mesosoma, while L. grandidieri is characterized by the presence of sculpture on the sides of the mesosoma.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Habitat

This species is restricted to the rainforest of the RS Manongarivo in northwestern Madagascar

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.

  • . Leptogenys Rakotonirina & Fisher, 2014: 60, figs. 27A, 70, 83 (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: 0.96–0.98, HL: 1.41–1.42, CI: 68–69, SL: 1.57–1.61, SI: 163–164, PW: 0.80–0.83, WL: 2.27–2.28, PNH: 0.59–0.60, PNL: 0.57–0.58, PNW: 0.42–0.42, DNI: 73–74, LNI: 103–105.

Head subrectangular and longer than broad; width greatest at about mid-length immediately behind the eye; side slightly convex, posterior margin more or less straight. In full-face view, eye medium-sized, maximum diameter roughly one-fourth the length of lateral cephalic border; breaking outline of sides of head. Antennal scape long, more than one-third of of its length surpassing posterior cephalic border. Length of third antennal segment less than twice the length of the second. Inner margin of mandible with short, angulate preapical tooth at its broadest width. In side view, propodeal posterior margin with toothlike lobe at level of spiracle. With petiole in lateral view, posterodorsal angle slightly overhanging posterolateral margin of node; node inclined, anterior face short, forming a convex line with dorsal margin, posterior face high; node relatively higher than long. Mandible finely microreticulate, with sparse punctulae; median lobe of clypeus coarsely striate. Lateral surface of mesosoma generally smooth and shining; propodeal declivity distinctly transversely striate. Dorsum of head and body covered with standing hairs and pubescence. Color dark brown to brown; appendages and gaster brown with much lighter apices.

Type Material

Holotype worker: Madagascar, Antsiranana, RS Manongarivo, 12.8 km 228° SW Antanambao, -13.9767, 48.4233, 780 m, rainforest, ground forarger, 11–17 Oct. 1998 (B.L. Fisher) collection code BLF01859, specimen code: CASENT0247267 (California Academy of Sciences). Paratypes: 6 workers with the same data as holotype but with the following specimen codes: CASENT015360, CASENT0196539, CASENT0196540, CASENT0247269, CASENT0247268, CASENT0247270 (CASC, The Natural History Museum, Musee d'Histoire Naturelle Genève, Parc Botanique et Zoologique de Tsimbazaza).

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.