Leptogenys alluaudi

This species generally forages on the forest floor as well as in leaf litter, and nests mostly in rotten logs and rarely in rotting tree stumps.

Identification
A member of the alluaudi complex of the incisa species group. Rakotonirina and Fisher (2014) - Worker. Peg-like setae absent near the anterior margin of median lobe of clypeus; head nearly subquadrate, eye not breaking lateral cephalic margin, basal portion of mandible slightly curved, not extending beyond outline of the sides of head.

Leptogenys alluaudi is sympatric with Leptogenys pilaka in the PN Montagne d'Ambre and both species appear to be closely related to each other. Together with Leptogenys incisa, they constitute the alluaudi species complex. They look very similar in body size, shape of the clypeus, and absence of peg-like setae on the anterior clypeal margin. Leptogenys alluaudi is one of the largest species within the group (HW: 2.20–2.50). It can be distinguished from L. pilaka and L. incisa by its subquadrate head (CI: 97–103) and the position of its eyes, which do not break the lateral border of the head. In L. pilaka and L. incisa, the head is elongate (CI: 85–97) and the eyes project beyond lateral margins of head in full face view.

Distribution
Northern Madagascar.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Habitat
It has been recorded in dry forest, littoral forest, and montane rainforest.

Nomenclature

 *  alluaudi. Leptogenys alluaudi Emery, 1895f: 338 (w.) MADAGASCAR. See also: Bolton, 1975a: 297.

Worker
Rakotonirina and Fisher (2014) - (12 specimens). HW: 2.20–2.50, HL: 2.25–2.55, CI: 97–103, SL: 2.30–2.61, SI: 97–107, PW: 1.46–1.62, WL: 3.62–4.01, PNH: 1.21–1.31, PNL: 1.06–1.16, PNW: 1.01–1.16, DNI: 94–103, LNI: 107–119.

Head generally as broad as long or broader than long; lateral border weakly convex and feebly diverging anteriorly throughout their length. Eye large, not breaking sidelines of head. Antennal scape relatively short (SI: 97–107), less than one third of apical portion surpassing posterior cephalic margin. Clypeus concave laterally and strongly converging anteriorly, ending in narrow angular lobe with fringing lamella. Mandible elongate and narrow, feebly curved near base; with concave inner margin; blades not strongly crossing each other and not closing tightly against clypeus; basal groove narrowly impressed. Mesosoma in profile high and short; propodeal lobe absent. With petiole in side view, node about as high as broad; straight and vertical anterior face and anteriorly sloping posterior meeting convex dorsal margin at rounded angle. Third and fourth abdominal segments with feeble constriction between them. Mandible mostly smooth, with scattered punctures and faintly effaced striation. Head reticulate-rugose dorsally; sides and posterior third finely microreticulate with sparse, large punctures. Mesosoma and petiolar node densely and finely reticulate-rugose to microreticulate, superimposed with scattered large and elongate punctures; declivitous surface with transverse rugulae. Third and fourth abdominal tergites smooth apart from widely spaced punctures. Standing yellowish hairs present on entire dorsum of body with less pubescence. Color black; tip of gaster and appendages brown to reddish brown.

Type Material
Rakotonirina and Fisher (2014) - Holotype worker, Madagascar, Diego Suarez, Avril-August, 1893 (Alluaud) [examined].

References based on Global Ant Biodiversity Informatics

 * Emery C. 1895. Mission scientifique de M. Ch. Alluaud dans le territoire de Diego-Suarez (Madagascar-nord) (Avril-août 1893). Formicides. Annales de la Société Entomologique de Belgique 39: 336-345.
 * Fisher B. L. 1997. Biogeography and ecology of the ant fauna of Madagascar (Hymenoptera: Formicidae). Journal of Natural History 31: 269-302.
 * Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.
 * Rakotonirina J. C., and B. L. Fisher. 2014. Revision of the Malagasy ponerine ants of the genus Leptogenys Roger (Hymenoptera: Formicidae). Zootaxa 3836 (1): 001163.