Leptogenys tatsimo

Every Ant Tells a Story - And Scientists Explain Their Stories Here
Jump to navigation Jump to search
Leptogenys tatsimo
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. tatsimo
Binomial name
Leptogenys tatsimo
Rakotonirina & Fisher, 2014

Leptogenys tatsimo casent0122874 p 1 high.jpg

Leptogenys tatsimo casent0122874 d 1 high.jpg

Specimen Labels

Leptogenys tatsimoi s a humid forest dweller of southeastern Madagascar. The species nests in rotten logs and forages on the forest floor.


A member of the imerinensis complex of the incisa species group. Rakotonirina and Fisher (2014) - Worker. Anterior border of medial clypeal lobe with anteriorly projecting, sA member of the imerinensis complex of the incisa species group. mall peg-like setae from above much broader semi-translucent lamella; lamella width as great as minimum diameter of antennal scape; scape relatively long (SI 144–147), more than apical third portion extending beyond posterior cephalic margin. Mandible roughly broad and smooth apart from short striation and sparse punctures; blades strongly curved near base, increasing in width toward apical section. In dorsal view, dorsum of mesosoma consisting of four segments, with an additional suture between metanotal groove and propodeum.

Leptogenys tatsimo and Leptogenys manja look very similar, but L. tatsimo has a broader mandible, a conspicuous fringing lamella on the clypeus, and an additional suture between the metanotal groove and the propodeum in dorsal view (four apparent segments on the dorsum of the mesosoma). Leptogenys manja is characterized by the slender mandibular blades, a narrow, semi-translucent lamella on the clypeus, and three mesosomal segments in dorsal view.

Keys including this Species


Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


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.



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

  • tatsimo. Leptogenys tatsimo Rakotonirina & Fisher, 2014: 101, figs. 49A, 51A, 109, 125 (w.) MADAGASCAR.

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



(3 specimens). HW: 1.53–1.68, HL: 1.90–2.06, CI: 81–82, SL: 2.25–2.44, SI: 144–147, PW: 1.23–1.31, WL: 3.46–3.54, PNH: 0.92–1.02, PNL: 1.01–1.07, PNW: 0.85–0.95, DNI: 84–88, LNI: 91–95.

In full-face view, head elongate and slightly increasing in width toward the front of eye; sides broadly convex. Eye somewhat protruding, position dividing lateral margin of head. Antennal scape particularly long, with more than one third of its length surpassing posterior cephalic margin. Anteromedian lobe of clypeus broadly angulate with a blunt apex, connected with generally convex lateral margin and bordered with wide, fringing, semi-translucent membrane. Mandible long and broad, strongly curved near base; gradually increasing in width, apical tooth obtuse; not capable of closing tightly against median lobe of clypeus if apices superimposed. In full-face view, hypostomal teeth not visible. With mesosoma in dorsal view, metanotal groove impressed, additional shallow and fine transverse sulcus present between metanotal groove and propodeum; in lateral view, propodeal dorsum roughly straight and elongate, joining distinctly short declivity in blunt angle. Petiolar node in profile more or less elongate, with anterior and posterior margin rounding to convex dorsal margin. Constriction between third and fourth abdominal segments strong. Mandible generally smooth apart from faint short striation and sparse punctures. Dorsum of head and mesosoma densely reticulate-rugose; propodeal declivity rugulose. Lateral portion of petiolar node reticulate-rugose, and dorsally finely microreticulate, with sparse large punctures. Body dorsum covered with standing hairs and pubescence. Color black; apex of appendages and extremity of gaster ferruginous-brown.

Holotype Specimen Labels

Type Material

Holotype worker: Madagascar, Toliara, Grand Lavasoa, 25.9 km W Tolagnaro, -25.0877, 46.749, 450 m, rainforest, ex rotten log, 30 Nov 2006 (B.L. Fisher et al.) collection code: BLF15384, specimen code: CASENT0122874 (California Academy of Sciences). Paratypes: 4 workers, same data as holotype but specimen coded: CASENT0247279, CASENT0247280, CASENT0247281, CASENT0247282 (CASC, The Natural History Museum, Musee d'Histoire Naturelle Genève).


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