Leptogenys serrata

One specimen was recorded as found in leaf litter.

Identification
Key to Leptogenys of the New World

Lattke (2011) - A member of the famelica species group. Eye convex, occupies less than one-fourth of lateral cephalic margin, situated slightly dorsolaterally; clypeus mostly smooth medially and posterolaterally close to tentorial pit, anterolaterally with oblique to longitudinal striae; mesonotum broader than long in dorsal view; petiole subtriangular in lateral view, anterior and dorsal margins joined by single convex curve, node highest posterad.

This species can be confused with another Central American species of the famelica group, Leptogenys pinna, on account of its similar size but can be separated by comparing the elongate mesonotum and petiole of L. pinna, as well as the more posterolateral facing propodeal spiracle of L. pinna.

Leptogenys pittieri is similar in build, but has a single pre-apical tooth on the mandibular masticatory margin and a much more subquadrate petiolar node in lateral view.

Distribution
This taxon is known from Panama and Colombia.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Panama.

Castes
Queens and males are unknown.

Nomenclature

 *  serrata. Leptogenys serrata Lattke, 2011: 172, fig. 28 (w.) PANAMA.

Probably more species from this group are to be discovered as indicated by specimens that apparently represent different morphs, but since they are single specimens, there is not enough information for making sound decisions. Two workers with a petiole shaped similarly as L. serrata have been studied but they differ by having the propodeal spiracle on an elevation and its opening facing more posteriorly, relatively larger eyes, and the clypeus with a distinct narrow strip of smooth cuticle along its anterolateral margin. One is from Parque Nacional La Paya, Putumayo, Colombia and the other is from from Caxiuanã, Pará, Brazil (MEPG). These specimens have been labeled as Leptogenys cf. serrata. Hopefully a future reviser can make sense of these patterns.

Worker
Metrics, holotype (paratypes, n = 2): HL 1.28 (1.25-1.31); HW 0.81 (0.81-0.81); ML 0.64 (0.64-0.67); EL 0.20 (0.20-0.20); SL 1.55 (1.55-1.58); PW 0.74 (0.71-0.78); WL 2.19 (2.16-2.22); PH 0.84 (0.74-0.78); PL 0.67 (0.61-0.67); DPW 0.57 (0.57-0.57) mm. CI 0.63 (0.62-0.65); MI 0.79 (0.79-0.83); OI 0.25 (0.25-0.25); SI 1.92 (1.92-1.96); LPI 1.25 (1.10-1.28); DPI 0.85 (0.85-0.94).

Head elongate in full-face view, wider anterad than posterad; lateral cephalic margin broadly convex; posterior cephalic margin convex; median clypeal process broadly triangular, laminate, apex pointed; lateral clypeal process narrow, joining smoothly with base of median process. Eye convex, occupies less than one-fourth of lateral cephalic margin, situated slightly dorsolaterally, anterad of mid-length of lateral cephalic margin. Cephalic dorsum mostly smooth and shining with abundant punctulae, and scattered piligerous punctae; clypeus mostly smooth medially and posterolaterally close to tentorial pit, anterolaterally with oblique to longitudinal striae; longitudinal sulcus extends posterad from between frontal carinae to one-half eye height; clypeus and frontal carina protrude dorsally in lateral view, clypeal margin broadly convex; head ventral surface smooth and shining with scattered punctae. Scape densely punctulae, with abundant subdecumbent pilosity and scattered subdecumbent to suberect hairs, scape extends beyond posterior cephalic margin by half its length; third antennal segment over 2 x longer than its apical width, second antennal segment over half length of third segment; fourth antennal segment over three-fourths length of third segment, funicular segments subcylindrical. Mandible elongate, triangular, masticatory margin concave, mostly serrate, occasionally with denticle or two, length of masticatory margin almost same as basal margin; dorsal mandibular surface smooth with scattered punctae; PF: 4,3.

Mesosoma with deep metanotal groove separating convex promesonotal margin in lateral view from broadly convex dorsal propodeal margin; mesosomal sculpture mostly smooth and shining with scattered piligerous punctae. Mesometapleural suture scrobiculate, well impressed along mesopleuron; metapleural-propodeal suture lacking; propodeal spiracle not elevated, oval, oriented laterally with slight posterior angle; bulla of metathoracic spiracle convex; mesopleuron with weak fine transverse striae in some areas, some striae present posteroventrad, anteroventral carina well developed, forming angular lobe anterad; mesosternum mostly smooth with transverse striae anterad; metapleuron with transverse striae posteroventrad; declivitous propodeal face with transverse striae posterad; propodeum rounded, without lateral lobe or tooth; mesonotum broader than long in dorsal view, anterior margin convex; metanotal groove straight, scrobiculate to relatively smooth.

Petiole subtriangular in lateral view, anterior and dorsal margins joined by single convex curve, node highest posterad, posterior margin mostly straight to weakly convex. Transverse section of node at midlength has convex lateral outline. Subpetiolar process lobe-shaped in lateral view. Node longer than wide in dorsal view, anterior margin convex; lateral margin broadly convex, posterior margin straight; width of anterior margin more than half of posterior margin. Node smooth and shining, posterior face not sharply separated from lateral face. Anterodorsal postpetiolar margin convex in lateral view; gaster with scattered punctulae, constriction between abdominal segments III and IV weak; procoxae smooth and shining in lateral view. Mesosoma mostly with no pilosity, only scattered standing to suberect hairs; decumbent to appressed pilosity present on cephalic dorsum and legs. Head, mesosoma, node and most of gaster black to dark brown; antenna, mandibles, clypeus, legs, and apex of gaster ferruginous to ferruginous brown. Apex of pro- and metatibia without setae; mesotibial apex with single external seta.

Type Material
Holotype worker. Panama, Canal Zone, Barro Colorado Island, 15.viii.1938, N.A. Weber 1195, 1w deposited in. – Paratypes. (1) One worker with same data as holotype, 1w MCZC. (2) One worker from same locality as holotype, 9.v.1976, S. Levings, 1w MCZC.

Etymology
The species name alludes to the serrate masticatory mandibular margin. It is derived from the Latin adjective for toothed as a saw, serratus.