Leptogenys chrislaini

This species is known only from the littoral forest of Ambondrobe near Vohemar and the humid forest of Makirovana near Sambava in northeastern Madagascar. It forages in leaf litter and nests in rotten logs.

Identification
Rakotonirina and Fisher (2014) - Worker. Median portion of clypeus abruptly projecting anteriorly into short, narrowly angulate lobe; small peg-like setae projecting anteriorly from near anterior margin of lobe; basal portion of mandible distinctly arched in full face view, but not extending laterally beyond cephalic outline; antennal scape relatively short; in full-face view, eye breaking lateral cephalic margin; head subquadrate; in lateral view, posterior border of petiolar node without constriction near its posteroventral angle.

Leptogenys chrislaini closely resembles Leptogenys barimaso but L. chrislaini can be separated by the abrupt projection of the anterior margin of the clypeus into a narrowly angulate lobe, the subquadrate head, and the strongly curved basal portion of the mandible. It can be confused with Leptogenys lavavava but the latter has an elongate head, spiniform anteromedial clypeal lobe, and broadly curved mandibular blades which extend laterally beyond the lateral cephalic margin. Populations of L. chrislaini from the two known localities show differences in some morphological characters. Worker specimens from Makirovana Forest are slightly larger and have longer antennal scapes than those from Ambondrobe.

Key to Malagasy Leptogenys

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  chrislaini. Leptogenys chrislaini Rakotonirina & Fisher, 2014: 81, figs. 48C, 58B, 59B, 98, 114 (w.) MADAGASCAR.

Worker
(9 specimens). HW: 1.51–1.73, HL: 1.80–2.01, CI: 83–88, SL: 1.64–2.11, SI: 104–133, PW: 1.07–1.23, WL: 2.76–3.14, PNH: 0.88–0.99, PNL: 0.84–1.00, PNW: 0.84–0.93, DNI: 88–108, LNI: 92–111.

Head subquadrate, sides almost straight and weakly rounding to a slightly concave posterior margin. Eye large and slightly protruding, maximum diameter greater than widest part of scape. Antennal scape relatively short, usually less than a fourth of its apical portion attaining posterior cephalic margin. Clypeus anteriorly projecting into narrowly triangular median lobe, borderedby bluntly triangular subopaque lamella. Mandible elongate, strongly curved near base, but not extending laterally beyond lateral cephalic border; feebly concave to almost straight towards the apex; basal groove narrow; preapical tooth or denticle may be present near sharp apical tooth. In full-face view, hypostomal teeth short and bluntly triangular. With mesosoma in dorsal view, metanotal groove impressed and transversely striate; in lateral view, propodeum relatively high and short; posterior margin of propodeum with blunt angles at level of propodeal spiracle. Petiolar node roughly as high as broad in profile, with anteriorly sloped posterior margin; constriction absent near posteroventral angle of node; in dorsal view, petiolar node as long as broad or slightly longer than broad. Constriction between third and fourth abdominal segments feebly visible. Mandible basally striate; median portion smooth with faint striation and scattered piligerous pits; about apical third portion densely and finely striate. Head dorsum reticulate-rugose to densely and finely reticulate-rugose, interspersed with punctures which become larger and more widely spaced near posterior margin. Mesosoma and petiolar node densely and finely reticulate-rugose, with scattered punctures; pronotal punctures much smaller than those on rest of mesosoma; propodeal declivity with transverse rugulae. Gastral tergites one and two finely microreticulate and with shallow, elongate large punctures. Entire body covered with slender erect hairs and very abundant pubescence. Antennal scape with suberect hairs shorter than maximum diameter of scape. Black species, with reddish-brown appendages having lighter apices.