Rogeria leptonana

Type specimens come from lowland rain forest, Colombian specimens from forest receiving about 2m strongly seasonal annual precipitation. Montane specimens from Costa Rica were taken under large rocks in a pasture; those from Panama were collected in debris under a stump in unknown habitat (Kugler 1994). The species is known from rainforest to strongly seasonal dry forest, in forest litter.

Identification
Kugler (1994) - creightoni species group. WL 0.54-0.66mm. Median clypeal apron concave to convex. Eye small, nearly circular. Propodeal spines small to absent. Mesosoma low, slender (MHI 0.78-0.90; PW jWL 0.53-0.58). Petiole with moderate to large keel. Postpetiolar node from above as in Fig. 66. Anterior lip of postpetiolar sternum not prominent. Sides of head distinctly macro- or microsculptured. Mesosoma rugose, sometimes with strongly microareolate sides. Erect hair on scapes and usually on extensor surfaces of tibiae.

The range of Rogeria innotabilis overlaps that of Rogeria leptonana at least in southern Mexico and Nicaragua, perhaps more, if queens are correctly assigned. Workers of innotabilis differ as follows: 1) no erect hair on scapes, 2) generally larger (WL 0.66-0.73mm), 3) clypeus evenly convex, 4) palpal formula 2,2, 6) postpetiolar node widest midlength and sternum moderately to strongly prominent.

See also Rogeria creightoni, Rogeria curvipubens, Rogeria alzatei, Rogeria inermis, and Rogeria neilyensis.

Distribution
Chiapas, Mexico to the northern coast of Colombia and also the Dominican Republic; from sea level to 1750m (Kugler 1994).

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Costa Rica, Dominican Republic, Guatemala, Honduras, Mexico, Panama.

Nomenclature

 *  leptonana. Rogeria leptonana Kugler, C. 1994: 58, figs. 66-70 (w.q.m.) PANAMA.

The nontype specimens from the high elevations of Costa Rica may belong to a distinct species defined by the complete absence of propodeal spines, but presently they seem linked to the types by the two specimens from Panama, which have intermediate spine length.

The different palpal formula of the workers and queens and the fact that workers and queens specimens come from different countries cause doubt about whether the queens are correctly assigned. But most morphological characters fit leptonana better than any other species. See also Rogeria curvipubens.

Worker
Holotype and Paratype. TL 2.1-2.3 (2.1), HL 0.50-0.55 (0.51), HW 0.43-0.46 (0.44), SL 0.32-0.34 (0.32), EL 0.05-0.07 (0.06) (7-10 facets), PW 0.32-0.36 (0.33), WL 0.57-0.61 (0.57), SpL 0.07-0.10 (0.07), PetL 0.20-0.23 (0.21), PpetL 0.12-0.13 (0.13)mm, CI O.83-0.86 (0.86), OI 0.1 1-0.15 (0.14), SI 0.73-0.75 (0.73), PSI 0. 12-0.16 (0.12), MHI 0.83-0.90 (0.83). N=4

Mandibles triangular, with 5 teeth and occasional denticle; basal tooth larger than penultimate tooth. Palpal formula 3,2. Median clypeal apron concave. Body of clypeus projecting slightly over edge of apron. Posterior outline of head wry weakly concave or flat. Nuchal groove indistinct in lateral view. Mesosoma dorsal profile nearly flat. Propodeal spines short with wide base, a bisecting line passes just above anteroventral corner of pronotum. Spiracle about 1 diameter from nearest edge of infradental lamella. Petiolar node small. Postpetiole widest in anterior half. Ventral profile of sternum concave; anterior tip not prominent.

Head rugose-areolate to areolate on laterodorsa and sides, transversely areolate-rugose on posterior head. Macrosculpture well defined on posterior head, weaker on dorsum and sides. Areolate microsculpture gives a granular appearance to dorsum and sides of head, where it largely obscures the weak macro sculpture; intervals on posterior head nearly smooth. Anterior edge of pronotal disc transversely rugose-areolate. Rest of promesonotal dorsum longitudinally rugose with occasional laterals; microsculpture cbscure. Mesosoma sides with confused areolate macro- and microsculpture; the latter quite strong, giving a granular appearance. Petiole appears granular, with vestigial overlying macrosculpture. Postpetiolar node smooth; sides and venter appear granular.

Mesosoma dorsum with more than 12 pairs of emergent erect hairs; nodes each with at least 2 pairs of long posterodorsally projecting hairs. Tibiae with erect hairs.

Body yellowish-brown to brownish-yellow; frontoclypeal area and appendages lighter, more yellowish.

Nontypes. TL 2.2-2.5, HL 0.54-0.60, HW 0.43-0.50, SL 0.34-0.40, EL 0.04-0.08 (5-9 facets), PW 0.33-0.35, WL 0.54-0.66, SpL 0.03 (no spines)-0.11, PetL 0.21-0.26, PpetL 0.12-0.16mm, CI 0.80-0.83, OI 0.09-0.12, SI 0.77-0.83, PSI 0.05 (no spines)-0.18, MHI 0.78-0.90. N=8

Type description extended as follows. Mandibles subtriangular in Dominican Republic specimens. Clypeal apron convex in the Chiriquí, Panama specimens and truncate in Chiapas and Dominican Republic. Body of clypeus not projecting beyond clypeal apron in Chiapas specimen. Basal tooth may equal penultimate basal in size. Scapes slightly longer (SI 0.77-0.83). The Ocosingo, Mexico specimen has slightly longer spines than types (PSI 0.18); Cerro Pico Blanco, Costa Rica specimens have very short spines (PSI 0.07-0.10) those from Panama are devoid of armature. Short propodeal spines of Costa Rican specimens are more inclined than in types; a bisecting line passes just below the axilla. Postpetiole of Chiapas and Pedernales, Dominican Republic specimens narrower than others (PpetW/PpetL1.23-1.28 vs. 1.41-1.56); Pedernales postpetioles are widest in posterior half. Microsculpture on head may be less distinct than in types. Panamanian specimens lack erect hair on extensor surfaces of tibiae and have only 9 pairs of erect hairs on the mesosoma dorsum.

Male
TL 2.9, HL 0.51-0.53, HW 0.55-0.56, SL 0.32-0.34, EL 0.25, PW 0.50-0.53, WL 0.91-0.95, PetL 0.32-0.33, PpetL 0.15-0.16mm, CI 1.04-1.10, SI 0.58-0.61. N=4.

All four specimens from a nontype nest series, Cerro Pica Blanco, near San José, Costa Rica. Mandible with 4 teeth. Clypeal margin convex. Antennal flagellomeres 2-11 subequal in length and width; not twisted. Lateral habitus shown in Fig. 69. Mayrian and parapsidal sutures present. Forewing venation as in Fig. 30 hind wing as in Fig. 37. Genitalia shown in Fig. 70. Mandibles smooth; clypeus nearly so. Head dorsum areolate; sides behind eyes rugose; posterior head rugose-areolate. Mesosoma longitudinally rugose on lateral pronotum and dorsal meso- and metapleura. Anterior and ventral mesopleura smooth. Ventral metapleura diagonally rugose. Anterior portion of mesonotum with vague effaced microsculpture; longitudinally rugose macrosculpture begins at level of wing and continues onto mesoscutellum. Propodeum areolate. Petiole microareolate, with a few weak, fine longitudinal rugae. Postpetiole and gaster smooth. Abundant erect and decumbent pilosity on scapes, head, mesosoma, waist, and gaster. Head brown, except for yellowish-brown frontoclypeal area and yellow mandibles. Rest of body and appendages brownish-yellow; gaster T1 and SI darker.

Queen
Possible Queens. —TL 2.6-2.8, HL 0.60-0.61, HW 0.52-0.53, SL 0.40, EL 0.12-0.13, PW 0.45, WL 0.73-0.78, SpL 0.14-0.17, PetL 0.28-0.30, PpetL 0.14-0.16mm, CI 0.86-0.88, OI 0.20-0.23, SI 0.75-0.77, PSI 0.19-0.22, MHI 0.92-0.97. N=2

Both queens collected on the north coast of Colombia. Though workers of leptonana are unknown from South America, these queens have strongest affinities to leptonana workers: Mandible with 5 teeth; basal as large as or larger than penultimate basal. Clypeal apron emarginate. Posterior outline of head flat. Propodeal spines wide. Propodeal spiracle 2 diameters from edge of infradental lamella. Mesosoma low. Petiolar peduncle with prominent lamellate keel; node short. Pygidium and sting apparatus as in workers.

Sculpture also as in workers. Microsculpture present but indistinct on head and mesosoma. Pronotum with 1-2 transverse rugae medially; laterally rugose. Meso- and metanota longitudinally rugose, with nearly smooth, shiny intervals. Meso- and metapleura longitudinally rugose, except for smooth, shiny mesokatepisterna. Dorsal face of propodeum smooth. Petiole, including peduncle, and postpetiole nearly smooth. There are differences, however. Palpal formula 2,2 in the dissected Guajiran queen (vs. 3,2 in workers). One queen has a nearly subrectangular postpetiole. Neither has erect hair on the tibiae.

Type Material
Holotype and paratype locality. PANAMA: Canal Zone, Barro Colorado Island; 2 workers including holotype, II-III-1943, #5059 (J. Zetek), lot 43 3035; 5 workers, VI-X-1943, #5105 (J. Zetek) [1 whole specimen slide mounted] USNM, lot 43-16534]; 4 workers, 14-II-1976 (A. Newton) ; 1 worker, 27-II-1976 (A. Newton) MCZ; 1 worker, I-1960, #B-9 (W. L. Brown & E. S. McCluskey) [mouthparts, sting] MCZ; 2 workers, 7-III-1975, FP#6 (C Toft & S. Levings).

Etymology
The name from leptos (G., slender) and nanus (L., dwarf) describes the habitus of this species.

References based on Global Ant Biodiversity Informatics

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 * INBio Collection (via Gbif)
 * Kugler C. 1994. A revision of the ant genus Rogeria with description of the sting apparatus (Hymenoptera: Formicidae). Journal of Hymenoptera Research 3: 17-89.
 * 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/
 * Perez-Gelabert D. E. 2008. Arthropods of Hispaniola (Dominican Republic and Haiti): A checklist and bibliography. Zootaxa 1831:1-530.
 * Philpott, S.M., P. Bichier, R. Rice, and R. Greenberg. 2007. Field testing ecological and economic benefits of coffee certification programs. Conservation Biology 21: 975-985.