Leptogenys rufa

Known from a few lowland localities along the Mexican and Central American Gulf of Mexico-Atlantic Coast.

Identification
Lattke (2011) - Head subquadrate in full-face view; median clypeal lobe with rounded apex and apical seta; eye small, no more than 4 ommatidia long; antennal segment 3 with strong basal constriction compared with following antennal segments, mesonotum 3 × wider than long in dorsal view; petiolar node wider than long, anterolateral margins form single convexity.

A member of the rufa species group. While it is usual for the second antennal segment to be quite constricted basad, and the third segment to a lesser degree in L. rufa the third segment has an unusually strong constriction. The mandible has a series of hairs along the basal margin but they are not stiff or seta-like as in the pusilla group, nor does the internal mandibular margin have the sinusoidal aspect of the pusilla species.

Distribution
It is known from southern Mexico to Honduras.

Distribution based on Regional Taxon Lists
Neotropical Region: Belize, Honduras, Mexico.

Castes
Queens and males are unknown.

Nomenclature

 *  rufa. Leptogenys (Lobopelta) rufa Mann, 1922: 14 (w.) HONDURAS. See also: Lattke, 2011: 210.

Worker
Lattke (2011) - Metrics (n =3): HL 0.82–0.84; HW 0.57– 0.58; ML 0.40 – 0.42; EL 0.07 – 0.07; SL 0.67 – 0.67; PW 0.48 – 0.48; WL 1.19 – 1.24; PH 0.50 – 0.55; PL 0.43 – 0.43; DPW 0.38 – 0.40 mm. CI 0.69 – 0.70; MI 0.71 – 0.71; OI 0.11 – 0.12; SI 1.14 – 1.18; LPI 1.15 – 1.27; DPI 0.88 – 0.92.

Head subquadrate in full-face view; lateral margin broadly convex; posterior cephalic margin weakly concave, almost straight; anterior clypeal margin with triangular median lobe, apex rounded with apical denticle and long hair laterad of denticle; lateral lobe narrow, broadly triangular; eye weakly convex in cephalic full-face view, forming weak angle with median cephalic axis with posterior margin slightly more separated from cephalic median axis than anterior margin; eye roughly equidistant between middle of lateral cephalic margin and mandibular insertion; eye small, no more than 4 ommatidia across, distance between eye and mandibular insertion greater than ocular diameter; head widest posterior to compound eyes, cephalic width slightly less anterad of eye. Scape surpasses posterior cephalic border by roughly 1 apical width; each funicular segment widest apicad; antennal segments III–VI approximately of same length each, apical width approximately equal to length; segment III with greater basal constriction than following segments. Mandibular basal margin broadly convex; masticatory margin short with blunt apical tooth, basal margin with row of 3–4 hairs along basal half; mandibular dorsum mostly smooth and shining with scattered punctulae; mandible mostly of same width in oblique ventral view. Cephalic dorsum mostly smooth and shining with sparse punctulae.

Dorsal mesosomal margin with shallow but well-defined metanotal groove in lateral view, pronotal margin broadly convex, propodeal margin mostly straight to weakly convex; curvature sharper at propodeal declivity, with triangular lobe at spiracular height; propodeal margin and dorsal margin of tooth joined by continuously curved margin in lateral view, with ventral margin of tooth overhanging propodeal declivitous margin. Mesosomal sides smooth and shining, mesometapleural suture distinctly impressed, uninterrupted or scrobiculate; metapleural-propodeal suture absent; propodeal spiracle relatively small, round to broadly elliptical with opening directed posterolaterally; depression located between spiracle and propodeal lobe; mesosomal dorsum smooth and shining, propodeal declivity smooth and shining to transversely striate. Prosternum smooth and shining; mesopleuron with fine anteroventral carina; mesonotum 3 × wider than long in dorsal view; metanotal groove scrobiculate, its width more than half the width of mesonotum.

Petiole node subquadrate in lateral view, slightly inclined anterad; anterior and posterior margins vertical, anterior margin less than half the height of posterior margin; node dorsal margin convex, without sharp lateral edges. Subpetiolar process subrectangular in lateral view with anterior margin much shorter than posterior margin and broadly convex ventral margin. Node wider than long in dorsal view, anterolateral margins form single convexity, posterior margin straight to weakly concave. Anterior margin of postpetiole roughly vertical up to half node height in lateral view before starting to curve; dorsal margin convex; constriction between abdominal segments III – IV well marked. Body ferruginous brown; legs and antenna yellowish brown. No applied pilosity, with sparse erect and semi-erect hairs. Tibial apices lacking setae.

Type Material
Lattke (2011) - Holotype worker: Honduras, Ceiba, ii.–iii.1922, Cat. No. 24442 (W.M. Mann) [examined].

The holotype label bears no date but Mann (1922) mentions the period between February and March of 1920 as the time when most ants mentioned in his 1922 paper were captured.

References based on Global Ant Biodiversity Informatics

 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Lattke J. E. 2011. Revision of the New World species of the genus Leptogenys Roger (Insecta: Hymenoptera: Formicidae: Ponerinae). Arthropod Systematics and Phylogeny 69: 127-264
 * 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.