Leptogenys toeraniva

Leptogenys toeraniva occurs in the lowland forest of RNI Betampona and Makirovana near Sambava. This species was mostly found foraging under leaf litter and rarely on the forest floor, even though many different collecting methods have been used to collect ants across Madagascar. In addition to its smaller eyes and its rarity, this result supports the idea that L. toeraniva is a hypogaeic species, living generally under the soil layers.

Identification
A member of the toeraniva species group. Rakotonirina and Fisher (2014) - Worker. Mandible capable of closing tightly against clypeus; eye small, maximum diameter less than greatest width of scape; in full-face view, head rectangular; antennal scape with erect hairs shorter than maximum width of scape; eye smaller, maximum diameter much less than the maximum width of scape. With petiole in lateral view, anterior face of node the same height as posterior face. In profile, helcium located generally near mid-height of anterior margin of third abdominal segment; prora voluminous and anteroventral section of third abdominal sternite rounded; prora and anteroventral angle separated by large indentation.

Leptogenys toeraniva is similar to Leptogenys bezanozano but easily identified by the presence of short, erect hairs on the antennal scape, transversely rugulose propodeal declivity, and the anterior and posterior margins of the petiolar node are the same height. Leptogenys bezanozano has erect hairs that are as long as or longer than the maximum width of its scape, a smooth, shiny propodeal declivity, and a shorter posterior face of the petiolar node.Workers collected from the two known localities differ in some morphological characters. Specimens from Betampona have smaller eyes whose maximum diameter is less than greatest width of scape; the mandible is smooth and shining; and the anteromedian lobe of the cypeus has a pair of anteriorly projecting peg-like setae. In contrast, worker specimens from Makirovana forest have larger eyes, the maximum diameter slightly greater than maximum diameter of scape; mandible smooth and shining on basal half and finely striate on distal half; and the anteromedian lobe of the clypeus with three anteriorly projecting peg-like setae.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  toeraniva. Leptogenys toeraniva Rakotonirina & Fisher, 2014: 136, figs. 3C, 3D, 4C, 4D, 5B, 153, 158 (w.) MADAGASCAR.

Worker
(4 specimens). HW: 0.85–1.01, HL: 1.21–1.45, CI: 69–73, SL: 1.16–1.49, SI: 132–147, PW: 0.74–0.87, WL: 1.90–2.24, PNH: 0.70–0.83, PNL: 0.70–0.83, PNW: 0.64–0.71, DNI: 83–93, LNI: 94–104. FIGURE 153. Leptogenys toeraniva holotype worker CASENT0072075.

Head oblong, lateral margin approximately straight from anterior portion of head to posterior third and rounding gradually to posterior border. Eye small, greatest diameter less than maximum width of scape. Clypeus projecting anteriorly into prominent triangular lobe; semi-translucent lamella on lateral and anteromedian lobes separated by impression or notch. Mandible with convex inner margin; blades widest at apical third and closing tightly against clypeus when at rest. In full-face view, antennal scape long, surpassing posterior cephalic border by one-third of apical portion. In dorsal view, metanotal groove distinct and cross-ribbed. Petiolar node noticeably longer than broad in dorsal view. In profile, node longer than high, with anterior and posterior faces at the same height and meeting the dorsal face in rounded angle; subpetiolar process double, consisting of anterior triangular tooth and posterior rounded lobe separated by indentation. In side view, helcium located approximately near mid-height of anterior margin of third abdominal segment; prora voluminous and anteroventral angle of third abdominal sternite rounded; prora and anteroventral section separated by strong indentation. Dorsum of head, promesonotum, petiolar node and gastral tergites generally smooth and shining, with scattered small punctures from which hairs arise. Sculptures of head in front of eye rugulose, which become punctate at level of eyes and sparsely punctate in posterior cephalic portion. Propodeal dorsum with faintly fine rugulae between punctures; propodeal declivity transversely striate. Scape with erect hairs shorter than greatest width of scape. Color dark brown, with lighter appendages and tip of gaster.

Type Material
Holotype worker: Province Toamasina, RNI Betampona, Camp Vohitsivalana, 37.1 km 338° Toamasina, -17.924, 49.1997, 390 m, rainforest, sifted litter, 28 Nov 2005 (B.L. Fisher et al.), collection code: BLF13125, specimen code: CASENT0072075. Paratype worker: from same locality as holotype, but -17.8867, 49.2025, 520 m, rainforest, ground forager, 2 Dec 2005 (B.L. Fisher et al.), collection code: BLF13322, specimen code: CASENT0067668 (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.