Leptogenys pusilla

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.

Identification
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.

Distribution
Known from Costa Rica and Panama.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Colombia, Costa Rica, Mexico, Panama.

Castes
Males are Unknown.

Nomenclature

 *  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.

Worker
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.

Queen
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) [examined]. The type specimens studied are 2 card-mounted workers from Jiménez, Costa Rica deposited in the.

References based on Global Ant Biodiversity Informatics

 * Basset Y., L. Cizek, P. Cuenoud, R. K. Didham, F. Guilhaumon, O. Missa, V. Novotny, F. Odegaards, T. Roslin, J. Schmidl et al. 2012. Arthropod diversity in a tropical forest. Science 338(6113): 1481-1484.
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * De La Mora, A., and S. M. Philpott. 2010. Wood-nesting ants and their parasites in forests and coffee agroecosystems. Environmental Entomology 39: 1473-1481.
 * Del Toro, I., M. Vázquez, W.P. Mackay, P. Rojas and R. Zapata-Mata. Hormigas (Hymenoptera: Formicidae) de Tabasco: explorando la diversidad de la mirmecofauna en las selvas tropicales de baja altitud. Dugesiana 16(1):1-14.
 * Emery C. 1890. Studii sulle formiche della fauna neotropica. Bull. Soc. Entomol. Ital. 22: 38-8
 * Emery C. 1894. Estudios sobre las hormigas de Costa Rica. Anales del Museo Nacional de Costa Rica 1888-1889: 45-64.
 * Emery C. 1911. Hymenoptera. Fam. Formicidae. Subfam. Ponerinae. Genera Insectorum 118: 1-125.
 * Fernández F. 2008. Subfamilia Ponerinae s.str. Pp. 123-218 in: Jiménez, E.; Fernández, F.; Arias, T.M.; Lozano-Zambrano F. H. (eds.) 2008. Sistemática, biogeografía y conservación de las hormigas cazadoras de Colombia. Bogotá: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, xiv + 609 pp.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
 * Gove, A. D., J. D. Majer, and V. Rico-Gray. 2009. Ant assemblages in isolated trees are more sensitive to species loss and replacement than their woodland counterparts. Basic and Applied Ecology 10: 187-195.
 * Groc S., J. H. C. Delabie, F. Fernandez, F. Petitclerc, B. Corbara, M. Leponce, R. Cereghino, and A. Dejean. 2017. Litter-dwelling ants as bioindicators to gauge the sustainability of small arboreal monocultures embedded in the Amazonian rainforest. Ecological Indicators 82: 43-49.
 * INBio Collection (via Gbif)
 * 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.
 * Longino J. T., and R. K. Colwell. 2011. Density compensation, species composition, and richness of ants on a neotropical elevational gradient. Ecosphere 2(3): 16pp.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Majer J. D., and J. H. C. Delabie. 1994. Comparison of the ant communities of annually inundated and terra firme forests at Trombetas in the Brazilian Amazon. Insectes Sociaux 41: 343-359.
 * Mirmecofauna de la reserva ecologica de San Felipe Bacalar
 * Siqueira de Castro F., A. B. Gontijo, W. Duarte da Rocha, and S. Pontes Ribeiro. 2011. As comunidades de formigas de serapilheira nas florestas semidecíduas do Parque Estadual do Rio Doce, Minas Gerais. MG.BIOTA, Belo Horizonte 3(5): 5-24.
 * Vasconcelos, H.L., J.M.S. Vilhena, W.E. Magnusson and A.L.K.M. Albernaz. 2006. Long-term effects of forest fragmentation on Amazonian ant communities. Journal of Biogeography 33:1348-1356
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wheeler W. M. 1923. The occurrence of winged females in the ant genus Leptogenys Roger, with descriptions of new species. American Museum Novitates 90: 1-16.