Strumigenys trinidadensis

Occurs in wet forest habitat in Costa Rica. It is known from arboreal foragers on low vegetation (Longino, Ants of Costa Rica).

Identification
Bolton (2000) - A member of the Strumigenys trinidadensis-group. S. trinidadensis is easily separated from Strumigenys vivax, the only other member of the group, as the two species have very different preapical dentition; see notes under vivax.

Longino (Ants of Costa Rica) - Apical fork of mandible with a single intercalary tooth; mandible with a strong preapical tooth, followed by one or more teeth and/or denticles that are variable in size and position; propodeal lamellae with strong dorsal and ventral teeth; gaster finely sericeous opaque, longitudinally striolate; gaster covered with brush of abundant long flagelliform setae.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Nicaragua, Panama, Peru, Trinidad and Tobago.

Nomenclature

 *  trinidadensis. Strumigenys trinidadensis Wheeler, W.M. 1922c: 12 (w.) TRINIDAD. Brown, 1954l: 61 (m.). See also: Bolton, 2000: 566.

Worker
Bolton (2000) - TL 3.3-3.7, HL 0.78-0.88, HW 0.62-0.70, CI 78-82, ML 0.53-0.58, MI 65-69, SL 0.56-0.63, SI 85-94, PW 0.38-0.40, AL 0.82-0.90 (12 measured).

Mandible with 2 preapical teeth, both small but distinct; distal tooth longer than proximal, distance between distal tooth and apicodorsal tooth greater than length of distal preapical tooth. Proximal preapical tooth set close to midlength of straight inner mandibular margin. Eye moderate, maximum diameter ca 0.10, with 8-9 ommatidia in the longest row. Pronotum marginate anteriorly. Propodeum with a sharp spine at top of declivity and with a spine or long acutely triangular tooth at base; the latter almost or quite as long as the former. Ventral surface of petiole with a very narrow spongiform crest that may be fragmented in some individuals. Disc of postpetiole densely sculptured, reticulate-punctate and with some weak rugular or costulate sculpture. Flagellate hairs present, distributed as noted above. Dorsum of head also with a pair of short erect hairs close to occipital margin.

Male
Brown (1954) - A specimen taken with workers at Tumupasa, Bolivia: TL 3.0, HL 0.55, WL 0.94, forewing L 2.6, greatest eye diameter 0.29 mm.; CI 112 (HW including eyes is 0.62 mm.). Straightline exposed length of a single mandible about 0.11 mm. Eyes very large, bulging, distant from mandibular insertions by about the mandibular length. Mesothorax bulky, dorsum flat, notaulices distinct anteriorly only; parapsidal furrows distinct. Scutum with longitudinal rugulation superimposed on reticulate ground sculpture. Upper propodeal teeth represented by subrectanglar projections subtended by gently concave lamelliform carinae.

Petiole claviform, node low and poorly differentiated from its peduncle, the dorsal surface of which slopes evenly and gradually up to the nodal summit. Postpetiole broader than long, disc convex. Both nodes with small but dense paired subspongiform pads in the posterolateral and posteroventral positions. Gaster feebly and indefinitely striate at extreme base; otherwise, like the nodes and most of the thoracic pleura, smooth and shining. Pilosity general and fairly abundant, of moderate- and medium-length fine, curved simple hairs, reclinate to inclined erect, not conspicuous. Wings densely covered with brownish microtrichia.

Veins of forewing with Rs+M obsolete, Mf3.4 obsolescent, Rs very weak and indefinite. Hamuli of hindwing 5.

Yellowish ferrugineous except for head and median section of scutum, which are blackish-brown.

The mandibles, as in other species, are much reduced; nevertheless, the acute apices are barely capable of being opposed at their extreme tips. The inner borders are nearly straight, outer borders convex, blades tapered to very acute apices. Genitalia of a second specimen from the same (Tumupasa) series have been dissected, and a figure of the volsella will be presented in another part of this revision. The genitalia are in the usual strumigenite pattern, and were fully retracted in the present cabinet specimens.

Type Material
Bolton (2000) - Holotype worker, TRINIDAD: nr Port of Spain (R. Thaxter) [examined].

References based on Global Ant Biodiversity Informatics

 * Baccaro F. B., J. L. P. de Souza, E. Franklin. V. Lemes Landeiro, and W. E. Magnusson. 2012. Limited effects of dominant ants on assemblage species richness in three Amazon forests. Ecological Entomology 37: 1-12.
 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Brown W. L. Jr. 1954. The neotropical species of the ant genus Strumigenys Fr. Smith: group of saliens Mayr. Journal of the New York Entomological Society 62: 55-62.
 * Brown W. L. Jr. 1962. The neotropical species of the ant genus Strumigenys Fr. Smith: synopsis and keys to the species. Psyche (Cambridge) 69: 238-267.
 * Fernandes I., and J. de Souza. 2018. Dataset of long-term monitoring of ground-dwelling ants (Hymenoptera: Formicidae) in the influence areas of a hydroelectric power plant on the Madeira River in the Amazon Basin. Biodiversity Data Journal 6: e24375.
 * 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.
 * 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)
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Longino J. T. 2013. Ants of Nicargua. Consulted on 18 Jan 2013. https://sites.google.com/site/longinollama/reports/ants-of-nicaragua
 * 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.
 * Lopes M. C., G. P. A. Lamarre, C. Baraloto, P. V. A. Fine, A. Vincentini, and F. B. Baccaro. 2019. The Amazonas-trap: a new method for sampling plant-inhabiting arthropod communities in tropical forest understory. Entomologia Experimentalis et Applicata https://doi.org/10.1111/eea.12797
 * Salazar F., and D. A. Donoso. 2013. New ant (Hymenoptera: Formicidae) records for Ecuador deposited at the Carl Rettenmeyer ant collection in the QCAZ Museum. Boletín Tecnico 11, Serie Zoológica 8-9: 151  177.
 * Silva R.R., and C. R. F. Brandao. 2014. Ecosystem-Wide Morphological Structure of Leaf-Litter Ant Communities along a Tropical Latitudinal Gradient. PLoSONE 9(3): e93049. doi:10.1371/journal.pone.0093049
 * Silva T. S. R., and R. M. Feitosa. 2019. Using controlled vocabularies in anatomical terminology: A case study with Strumigenys (Hymenoptera: Formicidae). Arthropod Structure and Development 52: 1-26.
 * Sosa-Calvo J. 2007. Ants of the leaf litter of two plateaus in Eastern Suriname. In Alonso, L.E. and J.H. Mol (eds.). 2007. A rapid biological assessment of the Lely and Nassau plateaus, Suriname (with additional information on the Brownsberg Plateau). RAP Bulletin of Biological Assessment 43. Conservation International, Arlington, VA, USA.
 * Sosa-Calvo J., T. R. Schultz, and J. S. LaPolla. 2010. A review of the dacetine ants of Guyana (Formicidae: Myrmicinae). Journal of Hymenoptera Research 19: 12-43.
 * Wheeler W. M. 1922. The ants of Trinidad. American Museum Novitates 45: 1-16.