Odontomachus biumbonatus

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Odontomachus biumbonatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Odontomachus
Species: O. biumbonatus
Binomial name
Odontomachus biumbonatus
Brown, 1976

Odontomachus biumbonatus casent0217537 p 1 high.jpg

Odontomachus biumbonatus casent0217537 d 1 high.jpg

Specimen Labels

Very widespread in the Amazon Basin, and so far as known, nests mainly in rotten wood.


Brown (1976) - A member of the Odontomachus haematodus group. This species, formerly misidentified as Odontomachus laticeps in some collections, is marked by large size, broad head and mandibles, shining, sparsely pubescent gaster, and above all, by the shape of its petiole. It is probably widespread also in lowland tropical forests in southeastern Brazil.

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: 10.8° to -19.83333333°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil, Ecuador (type locality), French Guiana, Guyana, Peru, Suriname.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.



Images from AntWeb

Odontomachus biumbonatus casent0270599 h 1 high.jpgOdontomachus biumbonatus casent0270599 p 1 high.jpgOdontomachus biumbonatus casent0270599 d 1 high.jpgOdontomachus biumbonatus casent0270599 l 1 high.jpg
Worker. Specimen code casent0270599. Photographer Ryan Perry, uploaded by California Academy of Sciences. Owned by PSWC, Philip S. Ward Collection.
Odontomachus biumbonatus casent0900610 h 1 high.jpgOdontomachus biumbonatus casent0900610 p 1 high.jpgOdontomachus biumbonatus casent0900610 d 1 high.jpgOdontomachus biumbonatus casent0900610 l 1 high.jpg
Paratype of Odontomachus biumbonatusWorker. Specimen code casent0900610. Photographer Ryan Perry, uploaded by California Academy of Sciences. Owned by NHMUK, London, UK.


The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • biumbonatus. Odontomachus biumbonatus Brown, 1976a: 131, fig. 22, pl. 1B (w.q.) ECUADOR, PERU, BRAZIL (Pará, Amazonas, Guaporé, São Paulo), GUYANA.
    • Type-material: holotype worker, 12+ paratype workers, 4 paratype queens.
    • Type-locality: holotype Ecuador: Prov. Napo, Limoncocha and vicinity, 00°24’S, 76°36’W (H.R. Hermann “no. 386 and strays, also strays by P.L. Kazan); paratypes: 12 workers with same data, workers Peru: Dept. Huanaco, Tingo Maria vic. nest no. R-9 (W.L. Brown & W. Sherbrooke), Peru: Monson Valley, nr Tingo Maria (E.I. Schlinger & E.S. Ross), 2 queens Peru: Dept. Cuzco, Quincemil, 700 m., ix.1962, at light (L. Peña), workers, 1 queen Brazil: Pará, Icoaraci, nr Belém, 31.viii.1962, nest no. B-21 (W.L. Brown), workers Pirelli Rubber Plantation, Iriboca, nest no. B-274 (P.F. Darlington), workers Utinga, nr Belém, no. B-116 (P.F. Darlington), workers Canindé, Rio Gurupá (B. Malkin), workers Amazonas, Ponta Negra, nr Manaus, M-156 (W.L. Brown), workers High Falls on Rio Tarumá, nr Manaus, no. M-103 (W.L. Brown), workers Guaporé, Madeira-Mamoré Railroad Camp 41, ca 306 km. SW Porto Velho (W.M. Mann), workers São Paulo, Caraguatatuba, Reserva Florestal, 40 km. (K. Lenko), queen Guyana: Kartabo, 31.viii.1920 (W.M. Wheeler).
    • Type-depositories: MZSP (holotype); MCZC, MZSP (paratypes).
    • Status as species: Kempf & Lenko, 1976: 61; Brandão, 1991: 362; Bolton, 1995b: 295; Rodriguez, J. 2008: 158; Bezděčková, et al. 2015: 124; Feitosa, 2015c: 99; Fernández & Guerrero, 2019: 538.
    • Distribution: Brazil, Colombia, Ecuador, Guyana, Peru.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Type Material

Holotype Museu de Zoologia da Universidade de Sao Paulo and 12 paratype workers MZSP, Museum of Comparative Zoology from Limoncocha and vicinity, Provo Napo, 00"24'S, 76°36'W, ECUADOR, H. R. Hermann No. 386 and strays, also strays by P. L. Kazan. Other paratypes: PERU : Dept. Huanuco, Tingo Maria vic., nest no. R-9, W. L. Brown and W. Sherbrooke. Monson Valley, near Tingo Maria, E. I. Schlinger and E . S. Ross. Dept. Cuzco, Quincemil, 700 m, Sept. 1962, 2 winged queens at light, L. Pena, BRASIL : Para: Icoaraci, near Belem, 31 Aug. 1962, W. L. Brown, nest no. B-21 with winged queen in rotten wood. Pirelli Rubber Plantation, Iriboca, nest no. B-274, P. F. Darlington. Utinga, near Belem, no. B-116, P. F. Darlington. Caninde, Rio Gurupa, B. Malkin. Amazonas: Ponta Negra, near Manaus, W. L. Brown, no. M-156. High falls on Rio Taruma near Manaus, W. L. Brown, no. M-103. Guapore: Madeira-Mamore Railroad Camp 41, about 306 km SW of Porto Velho (W. M. Mann). Sao Paulo: Caraguatatuba, Reserva Florestal, 40 m (K. Lenko). GUYANA : Kartabo, winged queen, 31 Aug. 1920, W. M. Wheeler. Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.



Holotype: TL 13.6, HL 3.66, HW (across vertex) 2.50, HW (across ocular prominences) 2.76, ML 1 .90, scape L 2.96, eye L 0.48, WL 3.76 mm; CI 68, MI 52, SI 118.

Paratypes (smallest worker, Rio Taruma, Amazonas): TL 10.3, HL 2.78, HW (vertex) 1.80, HW (ocular prominences) 2.08, ML 1.56, scape L 2.50, eye L 0.38, WL 3.00 mm; CI 65, MI 56, SI 139.

Holotype and 4 worker paratypes from 4 localities, including those with largest and smallest heads: TL 10.3-13.6, HL 2.78-3.72, HW (vertex) 1.80-2.50, ML 1.56-1.92, WL 3.00-3.76, SL 2.50-3.00 mm; CI 65-68, MI 52-56, SI 118-139, ex 36 paratypes from 9 localities.

Head and mandibles massive, form as in Odontomachus laticeps, vertex notably wider than trunk and gaster. Callows with finely serrate inner (ventral) mandibular borders and three stout sharp-edged teeth at apex, the basal most of these of these subrectangular and with 1-2 smaller supplementary points on proximal edge. Older specimens (most foraging workers) with the apical teeth more or less worn down to rounded stumps. Palpi segmented 4, 3. Striation of head complete on dorsum, moderately fine (6-7 striae per 0.1 mm sample square on middle of left half of vertex), extending nearly halfway down sides, shining. Antennal fossae and sides of head smooth and shining, usually bluish-opalescent. Mandibles nearly smooth above, shining, with a few coarse punctures. Outer borders of mandibles, like antennae, densely punctate, weakly shining, with dense appressed to decumbent pubescence. Scapes slightly surpassing posterior margins of head when held back. Cervical cavity and underside of head smooth and shining.

Trunk robust; metanotum developed as a depressed transverse band, separated from mesonotum by a narrow depression with short longitudinal rugae. Propodeum weakly convex in profile over anterior half, followed by a shallow concavity of variable extent. Anterior propodeal convexity usually weakly longitudinally sulcate as seen from above. Declivity short and moderately convex.

Pronotum finely striate in very varied patterns: whorled, longitudinal, oblique, or transverse, but normally with at least some transverse striation forming a posterior band; mesonotum and propodeum transversely striate, the striae coarser on propodeal declivity. Mesopleura smooth and shining, except for anterior and posteroventral ends, which have variable striation; smooth part often bluish opalescent.

Head in center of vertex with a pair of long, anteriorly inclined hairs (L 0.04-0.05 mm), and sometimes in front of these a few shorter decumbent to suberect hairs. Long oblique hairs also present on undersides of mandibles, anterior underside of head (a few very short, delicate erect hairs here also ) , and coxae, trochanters and basal half of undersides of femora. Pronotum with a group of 4-10 coarse, curved erect hairs, mostly 0.05-0.06 mm. long.

Pubescence on head moderately abundant but spaced, decumbent to appressed, crossing the striation in most places, and therefore easily seen at a magnification of 20x. On trunk, pubescence inconspicuous, more restricted, dilute, mostly directed caudad and appressed. Legs shining, finely punctulate and with dense, short decumbent pubescence, except posterior (mesial) surfaces of femora, which are smooth and shining.

Petiolar node shape as in fig. 22; the characteristic abruptly rooted apical spine is slender, acute and nearly erect, i.e., on or near the major axis of the node, and may even be tilted slightly cephalad. Posterior face of node vertically sulcate ; sulcus flanked near mid-height by a pair of low swellings, best seen in oblique posterolateral view, from which the species takes its name. Node shining, smooth or nearly so on all surfaces above the alutaceous basal part, with scattered punctures; fine decumbent pubescence directed upward on anterior face and sides.

First gastric tergum glassy smooth, often with bluish reflections, with scattered coarse punctures from which arise numerous tapered, -fine, yellowish hairs, subdecumbent to suberect, about 0.15 to 0.55 (mostly 0.3-0.4 mm.) long. Pubescence long (0.12-0.15 mm.) and fine, appressed to decumbent, conspicuous but not crowded, the separated hairs only rarely touching one another (Plate I, B). Remaining segments of gaster also shining, with a partly feeble alutaceous sculpture varying to smooth and shining, with punctures. In some samples, especially from Para and Amazonian Peru, even the disc and posterior part of the first gastric tergum may have a very faint microreticulum visible in good light at magnifications of about 40x or more, but this does not interfere with the shininess of the integument of this segment. All segments of gaster, both above and below, with numerous hairs and sparse pubescence like the first tergum.

Body color in mature workers dark reddish-brown to piceous, often appearing black or nearly so to the naked eye. Mandibles, antennae and legs usually a little lighter, castaneous.


Alate (4 specimens: 1 from Kartabo, Guyana; 1 from Icoaraci, Para, Brasil, colony series B-22, with workers; 2 from Quincemil, SE Peru): TL 14.2-15.1, HL 3.40-3.60, HW (vertex) 2.40-2.46, ML 1.86-1.94, scape L 2.92-3.06, WL 4.10-4.40, forewing L 8.4-9.0 mm.; CI 68-71, MI 54-55.

With the usual differences from the worker. Pronotum transversely, scutum longitudinally striate; scutellum nearly smooth to obscurely longitudinally striate, shining. Wings tinged with brown.


  • n = 22, 2n = 44, karyotype = 44A (Brazil) (Santos et al., 2009; Mariano et al., 2015).


References based on Global Ant Biodiversity Informatics

  • Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
  • Brown W. L., Jr. 1976. Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, tribe Ponerini, subtribe Odontomachiti. Section A. Introduction, subtribal characters. Genus Odontomachus. Stud. Entomol. 19: 67-171.
  • 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. Orivel, A. Dejean, J. Martin, M. Etienne, B. Corbara, and J. H. C. Delabie. 2009. Baseline study of the leaf-litter ant fauna in a French Guianese forest. Insect Conservation and Diversity 2: 183-193.
  • Kempf W. W. 1978. A preliminary zoogeographical analysis of a regional ant fauna in Latin America. 114. Studia Entomologica 20: 43-62.
  • Kempf W. W., and K. Lenko. 1976. Levantamento da formicifauna no litoral norte e ilhas adjacentes do Estado de São Paulo, Brasil. I. Subfamilias Dorylinae, Ponerinae e Pseudomyrmecinae (Hym., Formicidae). Studia Entomologica 19: 45-66.
  • Lozano-Zambrano F. H., E. Jimenez, T. M. Arias-Penna, A. M. Arcila, J. Rodriguez, and D. P. Ramirez. 2008. Biogeografía de las hormigas cazadoras de Colombia. Pp. 349-406. 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.
  • Scott-Santos, C.P., F.A. Esteves, C.R.F. Brandao. 2008. Catalogue of "Poneromorph" ant type specimens (Hymenoptera, Formicidae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulsos de Zoologia 48(11):75-88.
  • 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