Leptogenys avaratra

This species is only known from the dry forest habitats of Montagne des Francais in the north and the transitional humid forests of Antshabe near Daraina in the northeast of Madagascar. This rare species nests in rotten logs and forages through leaf litter.

Identification
A member of the toeraniva species group. Rakotonirina and Fisher (2014) - Worker. Mandible capable of closing tightly against clypeus; maximum diameter of eye less than greatest width of scape. In full-face view head subquadrate (CI: 78–82); in profile, helcium located very low near the anteroventral angle of third abdominal segment; prora voluminous and anteroventral section of third abdominal sternite rounded; indentation weakly visible between prora and anteroventral angle.

Worker specimens of L. avaratra are very similar to other species within the toeraniva species group, but can be separated by the square form of the petiolar node in dorsal view, and the location of the prora near the anteroventral angle of the third abdominal segment. In the other species in this group, the petiolar node is approximately as high as long in profile, and the prora is separated from the rounded anteroventral angle of third abdominal sternite by an indentation. This species has been found from two different sites. Specimens from the two sites differ in the extent and depth of the sculpture.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  avaratra. Leptogenys avaratra Rakotonirina & Fisher, 2014: 131, figs. 3A, 3B, 150, 155 (w.q.) MADAGASCAR.

Worker
(4 specimens). HW: 0.91–0.99, HL: 1.17–1.21, CI: 78–82, SL: 1.22–1.29, SI: 130–133, PW: 0.77–0.82, WL: 1.76–1.90, PNH: 0.65–0.70, PNL: 0.63–0.68, PNW: 0.58–0.66, DNI: 90–99, LNI: 102–107.

Head subquadrate, lateral margins nearly straight and joining posterior margin in convex line. Maximum eye diameter about half the greatest width of scape. Clypeus with convex lateral lobes which converge abruptly into narrow anteromedian lobe; lobe covered with semi-translucent lamella. Mandible short and narrow, inner margin convex at about apical third of length; blades capable of closing tightly against clypeus. Scape long, roughly one-third of its length extending beyond posterior cephalic margin. In dorsal view, metanotal groove visible but not cross-ribbed. With petiole in dorsal view, node roughly as long as broad; in profile node as broad as high, with vertically straight anterior and posterior faces, both of which round into broadly convex dorsal face. Helcium located at lower level near anteroventral angle of third abdominal segment. Prora relatively voluminous and anteroventral portion of third abdominal sternite rounded; prora and anteroventral section not separated by strong indentation. Constriction between third and fourth abdominal segments indistinct. Dorsum of head with sparse, shallow punctures. Dorsal surface of mesosoma, petiolar node, and abdominal tergites III and IV sparsely punctulate to punctate; elongate punctures sometimes present, with fairly effaced, fine rugulae. In profile, mesopleuron and lower lateral surface of propodeum and petiolar node reticulate-rugose; propodeal declivity transversely rugulose. Integument reddish brown, appendages and tip of gaster ferruginous-red.

Queen
HW: 0.90, HL: 1.12, CI: 80, SL: 1.10, SI: 121, PW: 0.72, WL: 1.64, PNH: 0.55, PNL: 0.55, PNW: 0.60, DNI: 109, LNI: 100.

Ergatoid queen looks very similar to worker due to its lack of ocelli, but differs by the short and broadly convex dorsal outline of the mesosoma, the anteroposteriorly flattened petiolar node and a much larger gaster.

Type Material
Holotype worker: Madagascar, Antsiranana, Montagne des Français, 7.2 km 142° SE Antsiranana (= Diego Suarez), -12.3228, 49.3382, 180 m, tropical dry forest, ex rotten log, 22–28 Feb 2001 (Fisher, Griswold et al.) collection code: BLF03177, specimen code: CASENT0416208. Paratypes: 1 ergatoid queen and 4 workers, with same data as holotype but with the following specimen codes: CASENT0416209 (ergatoid queen), CASENT0416210, CASENT0247238, CASENT0247239, CASENT0247240 (CASC,, , ).

References based on Global Ant Biodiversity Informatics

 * 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.