Eciton hamatum

von Beeren et al. (2018) found the Wasmannian mimic rove-beetle Ecitophya gracillima in colonies of this species in La Selva biological station in Costa Rica. An analysis of cuticular hydrocarbons showed both the ants and beetle had similar CHC profiles. Laboratory behavioral assays showed the beetles sought contact with host ants and often engaged in reciprocal grooming behavior with workers.

Identification
Jack Longino:

Minor worker: head, mesosoma, and metasoma evenly orange yellow; occipital tooth present; petiolar teeth in the form of short, acute flanges, separate or joined into a scoop-like structure, and with short separate carinae extending to a variable extent onto the posterior face, never fused into a single median carina on the posterior face; petiole long and low, subrectangular, with no anterodorsal elevated flange; fourth abdominal tergite with short, sparse appressed pubescence beneath erect setae.

Major worker: face smooth and shiny, not matte; long sickle-shaped mandibles simple, without tooth on inner margin; other characters as in minor.

Similar species: Eciton lucanoides.

Distribution based on Regional Taxon Lists
Neotropical Region: Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, Suriname, Trinidad and Tobago, Venezuela.

Biology
Jack Longino: In lowland wet forest habitats this is one of the most common Eciton species. Raids are always in columns, never in a carpet like Eciton burchellii. Raids can be day or night, and I frequently observe raiding columns ascending trees. Prey are often brood of vespid wasps and the ant genera Dolichoderus and Camponotus, suggesting that E. hamatum is mainly an arboreal forager.

Brown & Fenner (1998) report this species conducting raids on the nests of an unknown species of Pheidole at Pakitza, Peru.

O'Donnell et al. (2020) report this species foraging both day and night.

Castes

 * Worker

Nomenclature

 * . Formica hamata Fabricius, 1782: 494 (s.) FRENCH GUIANA.
 * Type-material: holotype worker.
 * Type-locality: French Guiana: Cayenne (no collector’s name).
 * Type-depository: ZMUC.
 * Mayr, 1886b: 121 (w.); Emery, 1896g: 39 (m.); Wheeler, W.M. 1925c: 145 (q.); Wheeler, G.C. 1943: 327 (l.).
 * Combination in Myrmecia: Fabricius, 1804: 425;
 * combination in Atta: Latreille, 1809: 129; Leach, 1815: 147;
 * combination in Eciton: Latreille, 1804: 179; Latreille, 1817c: 75; Smith, F. 1855c: 161;
 * combination in E. (Eciton): Emery, 1910b: 20; Santschi, 1925b: 12.
 * Status as species: Fabricius, 1787: 311; Gmelin, 1790: 2803; Olivier, 1792: 502; Fabricius, 1793: 364; Latreille, 1802c: 242; Fabricius, 1804: 425; Latreille, 1804: 179; Leach, 1815: 147; Latreille, 1817c: 75; Lamarck, 1817: 97; Smith, F. 1855c: 161; Smith, F. 1858b: 148; Mayr, 1863: 409; Roger, 1863b: 36; Norton, 1868a: 61; Norton, 1868b: 45; Mayr, 1886b: 117 (in key); Forel, 1886a: 217; Emery, 1890b: 38; Dalla Torre, 1893: 3; Emery, 1894c: 176; Emery, 1894k: 45; Forel, 1895b: 119; Emery, 1896g: 39; Forel, 1899c: 22; Emery, 1900a: 176 (in key); Wheeler, W.M. 1907a: 271; Forel, 1907e: 2; Emery, 1910b: 20; Forel, 1912c: 41; Mann, 1916: 419; Crawley, 1916b: 368; Forel, 1921b: 133; Santschi, 1921g: 88; Wheeler, W.M. 1921d: 309; Mann, 1922: 19; Borgmeier, 1923: 38; Wheeler, W.M. 1923a: 1; Wheeler, W.M. 1925a: 1; Santschi, 1925b: 12; Borgmeier, 1936: 51; Santschi, 1939f: 161; Borgmeier, 1953: 9; Borgmeier, 1955: 214 (redescription); Tafuri, 1957: 21; Borgmeier, 1958: 204; Kempf, 1960e: 387; Wheeler, G.C. & Wheeler, J. 1964c: 134; Kempf, 1970b: 323; Kempf, 1972a: 102; Watkins, 1976: 10 (in key); Watkins, 1982: 209 (in key); Wheeler, G.C. & Wheeler, J. 1984: 269; Bolton, 1995b: 185; Palacio, 1999: 152 (in key); Branstetter & Sáenz, 2012: 254; Bezděčková, et al. 2015: 109; Palacio, 2019: 601.
 * Senior synonym of amazona: Borgmeier, 1953: 14; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * Senior synonym of curvidentata: Shuckard, in Swainson & Shuckard, 1840: 174; Smith, F. 1858b: 148; Mayr, 1863: 409; Roger, 1863b: 36; Dalla Torre, 1893: 3; Forel, 1899c: 23; Emery, 1910b: 20; Borgmeier, 1923: 38; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * Senior synonym of funesta: Borgmeier, 1953: 13; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * Senior synonym of mattogrossensis: Borgmeier, 1953: 10; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * Senior synonym of pittieri: Borgmeier, 1953: 9; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * Senior synonym of testacea: Mayr, 1863: 409; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * Distribution: Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Panama, Peru, Suriname.
 * amazona. Eciton amazona Santschi, 1923d: 68 (s.w.) BRAZIL (Pará).
 * Type-material: 3 syntype workers.
 * Type-locality: Brazil: Pará, Monte Alegre (Reichensperger).
 * Type-depository: NHMB.
 * Subspecies of mattogrosense: Santschi, 1925d: 221.
 * Junior synonym of hamatum: Borgmeier, 1953: 14; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 184.
 * curvidentata. Formica curvidentata Latreille, 1802c: 269, pl. 8, fig. 55 (w.) FRENCH GUIANA.
 * Type-material: holotype(?) worker.
 * [Note: no indication of number of specimens is given.]
 * Type-locality: French Guiana: Cayenne (no collector’s name).
 * Type-depository: MNHN.
 * Combination in Eciton: Lepeletier de Saint-Fargeau, 1835: 179.
 * Status as species: Lepeletier de Saint-Fargeau, 1835: 179; Smith, F. 1855c: 162.
 * Junior synonym of hamatum: Shuckard, in Swainson & Shuckard, 1840: 174; Smith, F. 1858b: 148; Mayr, 1863: 409; Roger, 1863b: 36; Dalla Torre, 1893: 3; Forel, 1899c: 23; Emery, 1910b: 20; Borgmeier, 1923: 38; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 184.
 * funesta. Eciton hamatum var. funesta Santschi, 1921g: 89 (s.w.) COSTA RICA.
 * Type-material: 3 syntype workers.
 * Type-locality: Costa Rica: (no further data) (Ritter).
 * Type-depository: NHMB.
 * [Note: perhaps also in MHNG as Santschi says he received the specimens from Forel.]
 * Junior synonym of hamatum: Borgmeier, 1953: 13; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * mattogrossensis. Eciton (Eciton) hamatum var. mattogrossensis Luederwaldt, 1920: 4 (w.) BRAZIL (Mato Grosso).
 * Type-material: 7 syntype workers.
 * Type-locality: Brazil: Mato Grosso, Luiz de Cáceres (E. Garbe).
 * Type-depositories: MZSP, NHMB.
 * Santschi, 1925d: 221 (s.m.); Reichensperger, 1926: 401 (q.).
 * Subspecies of hamatum: Borgmeier, 1923: 38.
 * Status as species: Santschi, 1925d: 221.
 * Junior synonym of hamatum: Borgmeier, 1953: 10; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * pittieri. Eciton pittieri Forel, 1899c: 24, pl. 1, fig. 15 (w.) COSTA RICA.
 * Type-material: syntype workers (number not stated).
 * Type-locality: Costa Rica: Buenos Aires (Pittier).
 * Type-depository: MHNG.
 * Combination in E. (Labidus): Emery, 1910b: 23;
 * combination in E. (Holopone): Santschi, 1925b: 11.
 * Status as species: Emery, 1900a: 185; Emery, 1910b: 23.
 * Junior synonym of hamatum: Borgmeier, 1953: 9; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 185.
 * testacea. Camptognatha testacea Gray, G.R. 1832: 516, pl. 76, fig. 4 (w.) (no state data).
 * Type-material: holotype(?) worker.
 * [Note: no indication of number of specimens is given.]
 * Type-locality: none given.
 * Type-depository: unknown.
 * [Note: the entry in Gray, G.R. 1832: 516, says only, “We have also figured a species under the name of Camptognatha testacea, of Dr Leach’s MSS., but which may probably be the Eciton hamata of Latreille”.]
 * Junior synonym of hamatum: Mayr, 1863: 409; Borgmeier, 1955: 214; Kempf, 1972a: 102; Bolton, 1995b: 186.

References based on Global Ant Biodiversity Informatics

 * Adams B. J., S. A. Schnitzer, and S. P. Yanoviak. 2016. Trees as islands: canopy ant species richness increases with the size of liana-free trees in a Neotropical forest. Ecography doi: 10.1111/ecog.02608
 * Adams B. J., S. A. Schnitzer, and S. P. Yanoviak. 2019. Connectivity explains local ant community structure in a Neotropical forest canopy: a large-scale experimental approach. Ecology 100(6): e02673.
 * Aldana delq Torre R. C., and P. Chacon de Ulloa. 1999. Megadiversidad de hormigas (Hymenoptera: Formicidae) de la cuenca media del rio Calima. Revista Colombiana de Entomologia 25(1-2): 37-47.
 * Alonso L. E., J. Persaud, and A. Williams. 2016. Biodiversity assessment survey of the south Rupununi Savannah, Guyana. BAT Survey Report No.1, 306 pages.
 * Baroni Urbani C. 1977. Katalog der Typen von Formicidae (Hymenoptera) der Sammlung des Naturhistorischen Museums Basel (2. Teil). Mitt. Entomol. Ges. Basel (n.s.) 27: 61-102.
 * Borgmeier T. 1923. Catalogo systematico e synonymico das formigas do Brasil. 1 parte. Subfam. Dorylinae, Cerapachyinae, Ponerinae, Dolichoderinae. Archivos do Museu Nacional (Rio de Janeiro) 24: 33-103.
 * Borgmeier T. 1936. Sobre algumas formigas dos generos Eciton e Cheliomyrmex (Hym. Formicidae). Archivos do Instituto de Biologia Vegetal (Rio de Janeiro) 3: 51-68.
 * Borgmeier T. 1953. Vorarbeiten zu einer Revision der neotropischen Wanderameisen. Studia Entomologica 2: 1-51.
 * Borgmeier T. 1955. Die Wanderameisen der neotropischen Region. Studia Entomologica 3: 1-720.
 * Castano-Meneses, G., M. Vasquez-Bolanos, J. L. Navarrete-Heredia, G. A. Quiroz-Rocha, and I. Alcala-Martinez. 2015. Avances de Formicidae de Mexico. Universidad Nacional Autonoma de Mexico.
 * Coates-Estrada, R., and A. Estrada. 1989. Avian attendance and foraging at army-ant swarms in the tropical rain forest of Los Tuxtlas, Veracruz, Mexico. Journal of Tropical Ecology 5: 281-292.
 * Crawley W. C. 1916. Ants from British Guiana. Ann. Mag. Nat. Hist. 8(17): 366-378.
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Davidson, D.W. 2005. Ecological stoichiometry of ants in a New World rain forest. Oecologia 142:221-231
 * 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. 1896. Studi sulle formiche della fauna neotropica. XVII-XXV. Bullettino della Società Entomologica Italiana 28: 33-107.
 * Emery C. 1900. Nuovi studi sul genere Eciton. Memorie della Reale Accademia delle Scienze dell'Istituto di Bologna (5)8: 173-188
 * Escalante Gutiérrez J. A. 1993. Especies de hormigas conocidas del Perú (Hymenoptera: Formicidae). Revista Peruana de Entomología 34:1-13.
 * Esteves F. A., C. R. F. Brandao, and L. P. Prado. 2011. The type specimens of Dorylomorph ants (Hymenoptera, Formicidae: Aenictinae, Ecitoninae, Cerapachyinae, Leptanilloidinae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulsos de Zoologia 51(22): 341-397.
 * Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
 * Fernández F., E. E. Palacio, W. P. Mackay, and E. S. MacKay. 1996. Introducción al estudio de las hormigas (Hymenoptera: Formicidae) de Colombia. Pp. 349-412 in: Andrade M. G., G. Amat García, and F. Fernández. (eds.) 1996. Insectos de Colombia. Estudios escogidos. Bogotá: Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 541 pp
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Forel A. 1907. Formiciden aus dem Naturhistorischen Museum in Hamburg. II. Teil. Neueingänge seit 1900. Mitt. Naturhist. Mus. Hambg. 24: 1-20.
 * Forel A. 1921. Quelques fourmis des environs de Quito (Ecuador) récoltées par Mlle Eléonore Naumann. Bulletin de la Société Vaudoise des Sciences Naturelles 54: 131-135.
 * 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.
 * INBio Collection (via Gbif)
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Lattke J. E., M. Kaspari, S. ODonnell, and S. Powell. 2007. Las hormigas ecitoninas de Venezuela (Hymenoptera: Formicidae: Ecitoninae): elenco preliminar. Entomotropica Vol. 22(3): 153-170.
 * 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. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Luederwaldt H. 1920. Neue Brasilianische Ameisen. Sa~o Paulo: Weiszflog Irmaos, 14 pp
 * Maes, J.-M. and W.P. MacKay. 1993. Catalogo de las hormigas (Hymenoptera: Formicidae) de Nicaragua. Revista Nicaraguense de Entomologia 23.
 * Mann W. M. 1925. New beetle guests of army ants. Journal of the Washington Academy of Sciences 15: 73-77.
 * Medina U. C. A., F. Fernandez, and M. G. Andrade-C. 2010. Insectos: escarabajos coprofagos, hormigas y mariposas. Capitulo 6. Pp 197-215. En: Lasso, C. A., J. S. Usma, F. Trujillo y A. Rial (eds.). 2010. Biodiversidad de la cuenca del Orinoco: bases científicas para la identificación de áreas prioritarias para la conservación y uso sostenible de la biodiversidad. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, WWF Colombia, Fundación Omacha, Fundación La Salle e Instituto de Estudios de la Orinoquia (Universidad Nacional de Colombia). Bogotá, D. C., Colombia.
 * Mirmecofauna de la reserva ecologica de San Felipe Bacalar
 * Sandoval V. E., and G. Zambrano. 2007. Catálogo de las hormigas presentes en el Museo de Historia Natural de la Universidad del Cauca. Taller Editorial de la Universidad del Cauca, Popayán. 60 pp.
 * Santschi F. 1921. Ponerinae, Dorylinae et quelques autres formicides néotropiques. Bulletin de la Société Vaudoise des Sciences Naturelles 54: 81-103.
 * 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.
 * 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
 * Watkins II, J.F. 1982.The army ants of Mexico (Hymenoptera: Formicidae: Ecitoninae). Journal of the Kansas Entomological Society 55(2): 197-247.
 * Watkins J. F., II 1976. The identification and distribution of New World army ants (Dorylinae: Formicidae). Waco, Texas: Baylor University Press, 102 pp
 * Wheeler G. C. 1943. The larvae of the army ants. Ann. Entomol. Soc. Am. 36: 319-332.
 * Wheeler W. M. 1907. A collection of ants from British Honduras. Bulletin of the American Museum of Natural History 23: 271-277.
 * Wheeler W. M. 1921. Observations on army ants in British Guiana. Proceedings of the American Academy of Arts and Sciences 56: 291-328.
 * Wheeler W. M. 1925. The finding of the queen of the army ant Eciton hamatum Fabricius. Biological Bulletin (Woods Hole) 49: 139-149.