Odontomachus opaciventris

In Monteverde the diurnal foragers are common, and on warm days alate queens commonly fly into buildings. Nests are in rotten wood on the ground. Workers have been observed harvesting Calathea seeds. The species is rare at La Selva. (Longino, Ants of Costa Rica)

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

Biology
Colony sizes recorded as 5000, 8000, and 10000 workers, with one queen (De la Mora et al. 2008). Nest chambers spread throughout fallen logs as well as in superficial soil underneath.

In order to study both the hunting efficiency and the ﬂexibility of their predatory behavior, solitary hunters of the trap-jaw ant Odontomachus opaciventris  were offered small prey (termites, fruit ﬂies and tenebrionid larvae), presenting different morphological or defensive characteristics.The monomorphic hunters showed a moderately ﬂexible predatory behavior characterized by short capture sequences and a noteworthy efficiencyof their mandible strike (76.7–100% of prey retrievals), even when presented with  Nasutitermes  soldiers. Contrary to most poneromorph ants,antennal palpation of the prey before the attack was always missing,noparticular targeted region of the prey’s body was preferred,and no‘prudent’posture was ever exhibited. Moreover, stinging was regularly performed on bulky, fast moving fruit ﬂies, very scarcely with sclerotized tenebrionid larvae, but never occurred with Nasutitermes workers or soldiers despite their noxious chemical defense. These results suggest that, whatever the risk linked to potentially dangerous prey, O. opaciventris  predatory strategy optimizes venom use giving top priority to the swiftness and strength of the lethal trap-jaw system used by hunters as first strike weapon to subdue rapidly a variety of small prey, ranging from 0.3 to 2 times their own body size and from 0.1 to 2 times their weight. Such risk-prone predatory behavior is likely to be related to the large size of O. opaciventris colonies where the death of a forager might be of lesser vital outcome than in small colony-size species

Nomenclature

 * . Odontomachus haematodus r. opaciventris Forel, 1899c: 21, pl. 1, fig. 14 (w.q.) MEXICO (Tabasco), GUATEMALA, COSTA RICA, PANAMA, COLOMBIA.
 * Type-material: syntype workers, syntype queens (numbers not stated).
 * Type-localities: Mexico: Tabasco, Teapa (H.H. Smith), Guatemala: Cerro Zuníl, San Isidro, Pantaleon, and Mirandella (Champion), Costa Rica: Tuis (Pittier), Panama: Bugaba, Volcan de Chiriqui (Champion), Colombia: San Antonio, Don Diego (A. Forel).
 * Type-depository: MHNG.
 * Subspecies of haematodus: Forel, 1901h: 46; Forel, 1911e: 251; Emery, 1911d: 115; Forel, 1912c: 28; Borgmeier, 1923: 79.
 * Status as species: Kempf, 1972a: 172; Brown, 1976a: 105; Bolton, 1995b: 296; Rodriguez, J. 2008: 167; Branstetter & Sáenz, 2012: 262; Feitosa, 2015c: 99; Fernández & Guerrero, 2019: 539.
 * Distribution: Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, Panama.

References based on Global Ant Biodiversity Informatics

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 * Amat-G G., M. G. Andrade-C. and F. Fernández. (eds.) 1999. Insectos de Colombia. Volumen II. Bogotá: Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 433 pp. 131975
 * Andrade T., G. D. V. Marques, K. Del-Claro. 2007. Diversity of ground dwelling ants in Cerrado: an analysis of temporal variations and distinctive physiognomies of vegetation (Hymenoptera: Formicidae). Sociobiology 50(1): 121-134.
 * 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., G. Perez-Lachaud and J.P Lachaud. 2008. Mandible strike: The lethal weapon of Odontomachus opaciventris against small prey. Behavioural Processes 78: 64-75.
 * 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.
 * Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
 * Fernández F., and T. M. Arias-Penna. 2008. Las hormigas cazadoras en la región Neotropical. Pp. 3-39 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.
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 * Forel A. 1901. Formiciden aus dem Bismarck-Archipel, auf Grundlage des von Prof. Dr. F. Dahl gesammelten Materials. Mitt. Zool. Mus. Berl. 2: 4-37.
 * Forel A. 1911. Die Ameisen des K. Zoologischen Museums in München. Sitzungsber. Math.-Phys. Kl. K. Bayer. Akad. Wiss. Münch. 11: 249-303.
 * INBio Collection (via Gbif)
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
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 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Maes, J.-M. and W.P. MacKay. 1993. Catalogo de las hormigas (Hymenoptera: Formicidae) de Nicaragua. Revista Nicaraguense de Entomologia 23.
 * Marques G. D. V., and K. Del-Claro. 2006. The Ant Fauna in a Cerrado area: The Influence of Vegetation Structure and Seasonality (Hymenoptera: Formicidae). Sociobiology 47(1): 1-18.
 * 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.
 * Pires de Prado L., R. M. Feitosa, S. Pinzon Triana, J. A. Munoz Gutierrez, G. X. Rousseau, R. Alves Silva, G. M. Siqueira, C. L. Caldas dos Santos, F. Veras Silva, T. Sanches Ranzani da Silva, A. Casadei-Ferreira, R. Rosa da Silva, and J. Andrade-Silva. 2019. An overview of the ant fauna (Hymenoptera: Formicidae) of the state of Maranhao, Brazil. Pap. Avulsos Zool. 59: e20195938.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * da Silva de Oliveira A. B., and F. A. Schmidt. 2019. Ant assemblages of Brazil nut trees Bertholletia excelsa in forest and pasture habitats in the Southwestern Brazilian Amazon. Biodiversity and Conservation 28(2): 329-344.