Leptogenys quadrata

The type series was found under a stone.

Identification
Lattke (2011) - A member of the pusilla species group. Head elongate, rectangular in full-face view; eye broadly convex in cephalic full-face view, length less than one-fourth lateral cephalic margin; ocular center closer to mid-length of lateral cephalic margin than to mandibular insertion; petiole node subrectangular in lateral view.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Costa Rica, Ecuador.

Castes
Queens and males are unknown.

Nomenclature

 *  quadrata. Leptogenys quadrata Lattke, 2011: 196, fig. 50 (w.) COLOMBIA.

The paratype worker from the holotype nest is missing the gaster as well as several legs. The hair frequently present on the apex of the median clypeal lobe of this species suggests the seta found in other species groups, but it is never so stout as to be qualified as a seta.

The broad range of localities and altitudes, ranging from 1700 m to almost sea level, plus minor morphological differences suggest there could be more than one species under his name. See the comments for Leptogenys gorgona. Specimens from Magdalena, Colombia have more convex eyes, relatively larger ommatidia, and most of the propodeum smooth and shining. The Costa Rican specimen is very black, with striae on the mandibular dorsum. The worker from Ecuador is missing the petiole and gaster.

Worker
Metrics, holotype (paratypes, n = 4): HL 1.08 (0.94 – 1.06); HW 0.68 (0.58 – 0.64); ML 0.48 (0.38 – 0.44); EL 0.18 (0.12–0.16); SL 1.04 (0.82–0.92); PW 0.60 (0.54 – 0.62); WL 1.60 (1.34 – 1.52); PH 0.52 (0.52 – 0.58); PL 0.60 (0.54–0.62); DPW 0.36 (0.32–0.40) mm. CI 0.63 (0.60–0.62); MI 0.71 (0.63–0.72); OI 0.26 (0.20– 0.25); SI 1.53 (1.41–1.53); LPI 0.87 (0.90–0.97); DPI 0.60 ( 0.57 – 0.65).

Head elongate, rectangular in full-face view; lateral margin weakly convex; posterior cephalic margin straight to weakly convex; median clypeal lobe triangular, lateral margin straight to weakly concave, apex lamellate and pointed, sometimes with single hair; lateral lobe narrow and subparallel with clypeal margin; eye broadly convex in cephalic full-face view, length less than one-fourth lateral cephalic margin, ocular center closer to mid-length of lateral cephalic margin than to mandibular insertion. Scape smooth and shining with abundant piligerous punctulae, surpassing posterior cephalic border by not more than 3 apical widths; constriction between antennal segments II and III stronger than those of following segments; antennal segment III longer than either segments II and IV; length of antennal segment III twice apical width. Mandible elongate, external and basal margins parallel; basal margin weakly sinuate to mostly broadly convex, row of 2 – 3 setae present on basal convexity, apically weakly concave; basal angle rounded, masticatory margin short with single apical tooth; mandibular dorsum mostly smooth and shining with scattered punctulae; PF: 4,4. Cephalic dorsum and ventral face mostly smooth and shining with sparse punctulae; labium and stipes smooth and shining; clypeus with longitudinal striae and sparse piligerous tubercles medially, rest smoother.

Dorsal mesosomal margin mostly continuous in lateral view, straight to weakly convex; weak depression present at metanotal groove; propodeal dorsal margin curves smoothly with weakly convex declivity; propodeal tooth vestigial, low lobe with jagged margins present at spiracular height; mesosomal side mostly smooth and shining, with oblique striae at posteroventral corners of both mesopleuron and metapleuron; sparse striae present along mesopleural carina. Mesometapleural suture distinctly impressed, scrobiculate; metapleural-propodeal suture absent; propodeal spiracle relatively small, broadly oval with opening directed posterolaterally, bordered ventrad by longitudinal carina that extends to bulla; area between spiracle and bulla impressed; anteroventral carina of mesopleuron weakly widens anterad; mesosomal dorsum smooth and shining; propodeal declivity mostly with coarse transverse striae except for broad transverse sulcus next to petiolar insertion. Prosternum smooth and shining; mesonotum over twice wider than long in dorsal view, anterior margin convex, posterior margin straight; metanotal groove smooth.

Petiole node subrectangular in lateral view; anterior margin vertical, weakly convex; anterior margin more than half height of posterior margin; node highest posterad, dorsal margin convex, without sharp lateral edges. Subpetiolar process subrectangular in lateral view; wider posterad with anterior margin shorter than posterior margin. Node elongate in dorsal view, anterior margin weakly convex and less than half width of posterior margin, posterior margin straight, lateral margin straight to weakly concave. Node smooth and shining. Anterior margin of abdominal segment III weakly convex, dorsal margin convex; constriction between abdominal segments III–IV well marked. Body color mostly black to dark brown; mandible, clypeus, scape, legs brown; gastral apex ferruginous brown. Body with scattered erect and semi-erect hairs, appressed pilosity wanting. Coxae mostly smooth and shining; metacoxal dorsum with posterior rounded crest basad; pro- and metatibial apices lacking setae, mesotibia with or without apical seta.

Type Material
Holotype worker. Colombia, Valle, 15 km NW Cali, 1700 m, 12.xii.1975, J. Lattke. One worker deposited in. – Paratypes. (1) One worker from the same nest as the holotype deposited in MIZA. (2) Colombia, Valle, El Saladito, 03°26′14′′N 76°31′21′′W, 1650 m, vii.1997, C. Estrada. One worker deposited in.

Etymology
The species name is derived from the Latin, quadratus, meaning four-cornered, and alludes to the rectangular shape of the head in full-face view.

References based on Global Ant Biodiversity Informatics

 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/