Leptogenys ixta

Its collection at a relatively high altitude (1800 m. +) is unusual for a Ponerine ant.

Identification
Key to Leptogenys of the New World

Lattke (2011) - Mandible elongate, and relatively straight, becoming wider apicad; mandibular basal angle angular; median clypeal lobe extends apicad as prominent lobe, forming almost perpendicular angle at its base with each lateral lobe.

A member of the wheeleri species group. On account of the similar size and mandibles that expand apicad, this species may be easily confused with Leptogenys quirozi (see quirozi identification section for species specific characters).

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Biology
One outstanding biological character for this species is the altitude of the type locality, over 1800 m. Ponerines are not particularly abundant, nor diverse, at such an altitude, indicating that it may be a specialist in montane habitats such as Neoponera carbonaria (F. Smith) is in the northern Andes.

Dejean & Evraerts (1997) studied the predatory behavior of this species and other Leptogenys.

Castes
Queens and males are unknown.

Nomenclature

 *  ixta. Leptogenys ixta Lattke, 2011: 223, fig. 76 (w.) MEXICO.

Worker
Metrics, holotype (paratypes, n = 2): HL 1.48 (1.38–1.45); HW 1.18 (1.04–1.18); ML 0.94 (0.88– 0.94); EL 0.30 (0.30–0.34); SL 1.52 (1.48–1.48); PW 0.91 (0.88 – 0.88); WL 2.36 (2.22 – 2.26); PH 0.88 (0.91 – 0.94); PL 0.67 (0.61 – 0.67); DPW 0.71 (0.67 – 0.71) mm. CI 0.80 (0.72–0.85); MI 0.80 (0.74–0.90); OI 0.26 (0.26 – 0.32); SI 1.29 (1.26 – 1.42); LPI 1.30 (1.40 – 1.50); DPI 1.05 (1.05 – 1.11).

Head slightly elongate in full-face view, wider anterad than posterad; posterior margin broadly convex, vertexal carina visible; lateral cephalic margin very broadly convex, almost straight; lateral clypeal lobe extends from mandibular insertion to beneath median clypeal lobe, lobe broadly convex lateral, more convex mesad; median clypeal lobe triangular, apex rounded, with translucent margins. Clypeus striate; compound eye placed laterodorsally, slightly flattened, diameter approximately one-fourth that of lateral cephalic margin. Scape surpasses posterior cephalic border by over one-third its length; second and fourth antennal segments each more than half the length of third segment; funicular segments subcylindrical, with little or no constriction between each one. Mandible elongate, subfalcate, becoming wider apicad; dorsum shining, with fine parallel strigulae; masticatory margin edentate, does not shut tight against clypeus, leaving gap between clypeus proper greater than half the basal mandibular width; PF: 4,3.

Mesosoma with promesonotum and propodeum forming two separate, broad convexities in lateral view; mesopleuron elongate; anteroventral mesopleural carina thick, widest anterad, forms low angular lobe before anteroventral corner, anterior mesopleuron with brief shallow sulcus; mesometapleural suture well impressed; metapleural propodeal suture broad and shallow, deeper posterad than anterad; propodeal spiracle oval, facing posteriorly. Mesonotum wider than long in dorsal view; propodeum unarmed, declivitous face flat, transversely striate, striae coarser posterad.

Petiole subquadrate in lateral view, anterior margin slightly convex, dorsal margin straight, posterior margin vertical to weakly convex; subpetiolar tooth shaped as hooked lobe. Node subquadrate in dorsal view, slightly wider anterad than posterad; anterior margin broadly convex, posterior margin straight. Body and coxae, densely punctulate with a rough and opaque aspect, punctae finer and more spaced on posterior half of fourth abdominal tergite and posterad; apical gastral segments shine; hypopygidium with longitudinal smooth strip. Body lacks standing pilosity, except for scattered hairs on ventral side; body, antennae, and legs with abundant appressed pubescence. Antennae, clypeus, mandibles, legs, and fifth abdominal segment brown; apical abdominal segments ferruginous; head, mesosoma, and most of gaster brown-grey.

Type Material
Holotype worker. Mexico, D.F., Ixtapan de La Sal, 1829 m, 2.xi.1976, E.S. Ross. Deposited in. – Paratypes. Two workers with the same locality data as the holotype. Both deposited in CASC.

A worker in the is labelled as a Cotype (1-3, 20496) and considered as Leptogenys wheeleri, but there is no determination label on the pin with the ant and it clearly is not L. wheeleri, but L. ixta.

Etymology
The species name is derived from that of the type locality: Ixtapan de la Sal.