Leptogenys josephi Mackay and Mackay 2004

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

worker face view

worker lateral view

Upper images of worker; lower of queen.


Costa Rica to Panama. Costa Rica: Atlantic lowlands to 600m elevation, Guanacaste.


In usual resting position, mandibles flush against anterior border of clypeus; clypeus large and triangular, completely concealing labrum; median clypeal lobe with weak concavity along lateral margin; scape surpasses posterior cephalic border by 3 apical widths when placed parallel to logitudinal cephalic axis; antennal segments II-IV approximately twice their respective widths; posterior face of propodeum mostly smooth and shining, with 2-3 transverse striae close to petiolar insertion; petiolar node subcuboidal, with distinct vertical anterior and posterior faces in lateral view; face smooth and shining; petiole relatively longer in lateral profile compared to pusilla.

Worker metrics (n=5). HL (0.87-0.94); HW (0.55-0.62); ML (0.35-0.43); EL (0.12-0.13); SL (0.77-0.85); WL (1.20-1.34)mm. CI (0.63-0.68); MI (0.64-0.71); OI (0.19-0.23); SI (1.28-1.48).

Similar species: pusilla.

Natural History

This species inhabits the forest floor leaf litter in mature wet forest habitats. It is most often collected in Winkler samples of sifted leaf litter. The queens are peculiar, with grossly swollen, ivory-colored mandibles (MacKay and MacKay 2004).


This species was recently described by MacKay and MacKay (2004) based upon two queens from Costa Rica. During the separation of morphotypes close to L. pusilla, a group of workers and queens, both based upon larger size and more elongate basal funicular segments, has been separated and considered as conspecific with L. josephi. A queen from Panama is slightly smaller in size than the Costa Rican queens and presents a more convex dorsal propodeal margin in lateral view than the relatively straight to weakly convex shape of CR specimens. This species could be confused with L. JEL- qua, a morphologically similar species from western Colombia, Ecuador, and southern Costa Rica.

Type data

Leptogenys josephi Mackay and Mackay 2004:256. Holotype queen: Costa Rica, Guanacaste Province, Estacion Pitilla, 600m, 2 May 1995 (R. Anderson) [MCZC].

Literature Cited

MacKay, W. P. and E. E. MacKay. 2004. A new species of the ant genus Leptogenys (Hymenoptera: Formicidae) with inflated mandibles. Sociobiology 43:255-258.

Page authors:
John E. Lattke piquihuye@gmail.com
John T. Longino longinoj@evergreen.edu

Date of this version: 3 March 2009.
Go back to top

Go to Ants of Costa Rica Homepage