Leptogenys peruana

Identification
Key to Leptogenys of the New World

Lattke (2011) - Compound eye occupies not more than one-fourth of lateral cephalic margin in full-face view; mandible mostly straight in cephalic full-face view; basal margin gently convex, reaching greatest width two-thirds from base, tapering apicad; hypostomal tooth not visible in cephalic full-face view; propodeal dorsum mostly smooth and shining. Petiole half-dome shaped in lateral view; posterior margin sometimes with small blunt lobe that slightly overhangs posterior margin.

Within the unistimulosa group this species differs from the typical due to the proportionally smaller eyes, smoothened exoskeleton, and a reduced or missing petiolar apical lobe or tooth. The basal funicular segments have a slighter narrower base than the apex. The smoothened sculpturing and small size makes this species superficially resemble Leptogenys amazonica, but it is easy to separate on account of the more elongate petiolar node and the distinct apical tooth.

Distribution
This taxon is known from eastern Peru.

Castes
Queen, male. Unknown.

Nomenclature

 *  peruana. Leptogenys peruana Lattke, 2011: 216, fig. 72 (w.) PERU.

Worker
Metrics, holotype (paratypes, n = 2): HL 1.29 (1.16–1.27); HW 0.99 (0.91–0.96); ML 0.81 (0.76– 0.81); EL 0.20 (0.18–0.20); SL 1.52 (1.32–1.47); PW 0.76 (0.68 – 0.71); WL 2.15 (2.15 – 2.15); PH 0.81 (0.81 – 0.81); PL 0.63 (0.58 – 0.63); DPW 0.43 (0.43 – 0.43) mm. CI 0.76 (0.76–0.78); MI 0.82 (0.83–0.84); OI 0.21 (0.19–0.21); SI 1.54 (1.44–1.53); LPI 1.28 (0.00– 1.28); DPI 0.68 (0.68 – 0.74).

Head slightly elongate in full-face view, posterior border convex, curving onto straight lateral margin; head wider anterad than posterad; anterior clypeal margin laterally concave, lateral lobe long and broadly convex, median lobe forms broad triangle with blunt apex, 3 – 4 apical setae present. Diameter of compound eye not more than one-fourth length of lateral cephalic margin; eye convex, placed slightly dorsally, away from cephalic lateral margin. Scape surpassing posterior cephalic border by less than one-half its length; second antennal segment half as long as third; fourth antennal segment more than half the length of third; all antennal segments longer than broad. Mandible mostly straight in cephalic full-face view; basal margin gently convex, reaching greatest width two-thirds from base, tapering apicad; mandibular dorsum smooth and shining with sparse punctulae; masticatory margin slightly concave, separated from basal margin by corner. Cephalic dorsum mostly smooth and shining, with sparse piligerous punctulae; clypeus with transverse striae along anterior half. Gap between mandibular dorsal margin and clypeus at least half mandibular basal width, mandible almost touches lateral clypeal lobe in cephalic full-face view. External surface of labium and maxilla mostly smooth. Cephalic ventrum mostly smooth and shining. Hypostomal tooth brief, not projecting ventrad nor visible in anterior cephalic view.

Mesosoma with two dorsal convexities in lateral view, each formed by promesonotum and propodeal dorsum respectively; promesonotal dorsal margin broadly convex, almost straight, ascending until mid-mesonotal length; posterior half of mesonotum drops at an angle to metanotal groove; propodeal dorsum broadly convex, curving or separated by blunt angle onto straight declivity. Ventral pronotal groove weakly-impressed; propleuron and most of mesosomal sides mostly smooth and shining; metapleuron and ventral lateral propodeum with weak striae; propodeal dorsum mostly smooth and shining; bulla striate; mesometapleural suture well impressed, scrobiculate, forming ridge elevated above metapleuron. Metapleural-propodeal suture well impressed posterad as broad ridge, becoming weak along anterior one-fourth; metathoracic spiracular prominence rounded and convex; propodeal spiracle oval and facing posteriorly. Ventral mesonotal carina bends dorsally, almost at right angle before fading away at mid-width. Mesonotum longer than wide in dorsal view; propodeum unarmed, declivity with 4 – 5 transverse striae.

Petiole half-dome shaped in lateral view, with convex anterodorsal margin reaching summit just anterad of mostly vertical, slightly sinuate posterior margin; posterior margin sometimes with small blunt lobe that slightly overhangs posterior margin. Node mostly smooth ventrad, with longitudinal coarse striae dorsad; petiole longer than wide in dorsal view, anterior margin convex and more than half the width of posterior margin; posterior face smooth and shining. Gaster smooth and shining with sparse punctulae; pygidium broadly convex in lateral view, without median carina. Body with abundant erect to suberect hairs; scape with decumbent hairs and sub-decumbent pubescence; thorax and gaster with no or sparse pubescence. Procoxa smooth and shining in lateral view. Antennae, clypeus, coxae, and femora brown; mandibles and tibiae ferruginous brown; head, thorax, and most of gaster black.

Type Material
Holotype worker. Peru, 40 miles W Cusco, 4.iii.1951, subtropical cyn, E. Ross, M. Bacher, deposited in the. – Paratypes. Two workers with the same data as the holotype, each deposited in the CASC. Both paratype workers are missing their gasters.

Etymology
The species name is derived from the country of the type locality: Peru.