Leptogenys pusilla

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Leptogenys pusilla
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species: L. pusilla
Binomial name
Leptogenys pusilla
(Emery, 1890)

Leptogenys pusilla casent0178820 profile 1.jpg

Leptogenys pusilla casent0178820 dorsal 1.jpg

Specimen labels


The locality labels point to moist forested areas as the habitat for this species, ranging from secondary to primary forest or cocoa plantations. Nests have been found in decomposing wood on the ground. One specimen has a mite adhered to the apical internal side of the metatibia.


Lattke (2011) - Head subrectangular in full-face view; median clypeal lobe longer than basal width, apex acutely pointed; eye weakly convex, distance between eye and mandibular insertion greater than ocular diameter; mesonotum 4 × wider than long in dorsal view; petiolar node trapezoidal in dorsal view, anterior margin convex and at least half the width of posterior margin.

A member of the pusilla species group. This ant is very similar to Leptogenys josephi but L. pusillus is a smaller ant, compared with L. josephi (WL 1.20–1.34), and its head is not as elongate in appearance.

Keys including this Species


Known from Costa Rica and Panama.

Distribution based on Regional Taxon Lists

Neotropical Region: Colombia, Costa Rica (type locality), Mexico, Panama.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


The biology of Leptogenys pusilla is poorly known.

The Leptogenys genus page has more details about the general biology of ants in this genus, some of which is summarized in what follows. New World species have relatively small ranges, generally occur in humid forests and prey on isopods. Colonies may occur in high densities on a local scale, with up to 5 or 6 species present. Nest size tends to be small with just 20 or 30 individuals in a mature colony. Nests of most species may be found in rotten wood on the ground, usually within cavities in logs or large branches, and also beneath bark. Wood-soil and rock-soil interfaces are another common nesting location, as well as rock crevices, and a few species may nest directly in the soil. Reproduction is most commonly via ergatoid females and, in many species, may include egg-laying workers.


Males are Unknown.


The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • pusilla. Lobopelta pusilla Emery, 1890b: 43 (w.) COSTA RICA. [Also described as new by Emery, 1894k: 49.] Combination in Leptogenys: Forel, 1899c: 18. See also: Lattke, 2011: 195.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.



Lattke (2011) - Metrics (n = 4) : HL 0.72 – 0.87; HW 0.47 – 0.50; ML 0.28 – 0.35; EL 0.08 – 0.15; SL 0.53 – 0.75; PW 0.42 – 0.48; WL 0.94 – 1.22; PH 0.37 – 0.45; PL 0.37 – 0.48; DPW 0.27–0.27 mm. CI 0.58–0.65; MI 0.61–0.70; OI 0.18 – 0.30; SI 1.14 – 1.50; LPI 0.89 – 1.00; DPI 0.55 – 0.73.

Head subrectangular in full-face view; lateral margin broadly convex; posterior cephalic margin weakly concave, almost straight; anterior clypeal margin with abrupt, relatively slender (longer than basal width) median lobe, apex acutely pointed; lateral lobe narrow, laterally extends as low crest on clypeal dorsum, weakly rounded close to median lobe; eye weakly convex in cephalic full-face view, placed closer to middle of lateral cephalic margin than to mandibular insertion; eye about same length as mid-width of scape, 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 1–2 apical widths; basal funicular segments approximately of same length; width of each segment more than half respective length. Mandibular basal margin broadly convex basad, concave and tapering apicad; masticatory margin short with blunt apical tooth, basal convexity with row of 2–3 setae; mandibular dorsum mostly smooth and shining with scattered punctulae; mandible of same width in oblique ventral view. Cephalic dorsum mostly smooth and shining with sparse punctulae.

Dorsal mesosomal margin mostly continuous in lateral view, straight to weakly convex, weak depression present at metanotal groove; curvature sharper at propodeal declivity, with blunt, modest triangular lobe at spiracular height; mesosomal sides smooth and shining, mesometapleural suture distinctly impressed, uninterrupted or scrobiculate; metapleural-propodeal suture absent; propodeal spiracle round with opening directed mostly laterally, weakly oblique; 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 4 × wider than long in dorsal view, posterior margin with weak median concavity.

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 highest posterad, dorsal margin convex, without sharp lateral edges. Subpetiolar process triangular-shaped in lateral view. Node trapezoidal in dorsal view, anterior margin convex and at least half the width of posterior margin, posterior margin straight to weakly concave, lateral margins straight to slightly convex. Anterior margin of postpetiole roughly vertical up to node height in lateral view; dorsal margin convex; constriction between abdominal segments III – IV well marked. Body ferruginous brown to black; legs and antenna brownish yellow to brown. No applied pilosity, with sparse erect and semi-erect hairs. Tibial apices lacking setae.


Lattke (2011) - Morphology similar to worker, with usual differences besides greatly swollen mandible, with convex internal and external margins. Body ferruginous, mandible yellow.

Type Material

Lattke (2011) - Syntype workers: Costa Rica, Jiménez (A. Alfaro) (Museo Civico di Storia Naturale, Genoa) [examined]. The type specimens studied are 2 card-mounted workers from Jiménez, Costa Rica deposited in the Museo Civico di Storia Naturale, Genoa.