(Species Checklist, Species by Country)
|Based on Ward et al. 2016.|
Ortiz and Fernández (2014) - Brachymyrmex is a genus of minute ants that at first glance exhibit little morphological variation. Currently only the 9-segmented antennae and lack of antennal club have been proposed to diagnose workers of the genus (Bolton 2003). The combination of small size, soft metasoma, and the simple morphology makes observations and interpretation of morphological characters difficult. These difficulties impede taxonomic revisions and even led Creighton (1950) to call Brachymyrmex a “miserable little genus”. Nevertheless, 41 described species and subspecies are currently assigned to Brachymyrmex (Bolton, 2013). The genus has a mainly Neotropical distribution, ranging from the United States to Argentina and Chile, including the Caribbean islands (Kempf 1972, Brandão 1991, Bolton 1995, 2003), but some species have been introduced to Japan (M. Yoshimura, pers. comm.), and Madagascar (Dejean et al. 2010). More recently, Ortiz-Sepulveda et al. (2019) published a revision that: (1) redefined the limits of all of the described species, subspecies, and varieties in light of intra and interspecific morphological variation in workers; (2) documented this variation both qualitatively and quantiatively; (3) summarized these findings on diagnostic traits with a new, dichotomous, illustrated identification key to increase reproducibility and to make the diversity of Brachymyrmex more accessible for future research; and (4) examined the significance of our morphological identification system and the monophyly of the genus in light of molecular evidence. Finally, we also report on the biogeographical distribution of the recognized species and how our taxonomic framework compares with previous studies. In summary, we recognize a total of 40 species, 4 of which are newly described here. We also synonymize 25 previously described species/subspecies and raise two former subspecies to species status. This important revision was also stated to be work toward a comprehensive revision of Brachymymex. Remaining taxonomic work in the genus includes describing a number of putative new species. These remain undescribed due to there not being sufficient material and more collections are needed. There is also a need to determine if there are true intercastes present in a number of named species. This requires ovarian dissections and the collection of demographic data (Peeters 1991 ti insure these intercastes are not ergatoid queens. This problem also would be aided by additional collections of the Brachymyrmex species with intercastes.
- 1 Identification
- 2 Distribution
- 3 Biology
- 4 Castes
- 5 Morphology
- 6 Nomenclature
- 7 References
Minute ants (maximum length ~ 3 mm) with an acidopore and 9-segmented antennae that lacks an antennal club.
The combination of small body size, soft metasoma, and at least superficially monotonous external morphology complicate the observation and interpretation of morphological variation.
LaPolla and Longino (2006) - The genus Brachymyrmex is most likely to be confused with Myrmelachista. The most obvious distinction between these two genera is the presence of a 3 to 4-segmented antennal club in Myrmelachista. Although Brachymyrrnex usually possess incrassate antennae, they never form a distinct antennal club. Both genera include species with 9-segmented antennae, although Myrmelachista also includes some species with 10-segmented antennae (species in the synonymized subgenus Hincksidris [Snelling and Hunt 1975]). No Brachymyrrnex have been recorded with 10-segmented antennae. Two other morphological characteristics separate the two genera. The clypeus of Myrmelachista is typically subguadrate and compact, whereas Brachymynnex possess a broadly rounded (along the anterior margin) and wide clypeus. The shape of the mandible also differs between the two genera. In Myrmelachista, the masticatory and basal margins form a right angle. Whereas in Brachymynnex the masticatory and basal margins form an obtuse angle.
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Keys including this Genus
Keys to Species in this Genus
Distribution and Richness based on AntMaps
LaPolla and Longino (2006) - In Neotropical forests, the common species of Brachymyrmex nest in a variety of small plant cavities, under epiphytes, or in the leaf litter. They seem quite generalized in choice of nest site, and the nests can be in relatively fragile or ephemeral substrates, suggesting frequent nest movement. Brachymyrmex species seem to feed mainly at carbohydrate sources, being common at extrafloral nectaries and at sugar water baits. Some species are known to tend Coccoidea (Hemiptera) in underground chambers (Wheeler 1910; Santschi 1923). Very little is known about the natural history for the vast majority of Brachymyrmex species.
- Antennal segment count: 9
- Antennal club: absent-gradual, weak
- Palp formula: 6,4
- Total dental count: 5
- Spur formula: 0, 0
- Eyes: present
- Scrobes: absent
- Caste: monomorphic, dimorphic in a few species
- Sting: absent
- 2n = 18 (Brazil) (Crozier, 1970b).
All Karyotype Records for Genus
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- BRACHYMYRMEX [Formicinae: Plagiolepidini]
- Brachymyrmex Mayr, 1868b: 163. Type-species: Brachymyrmex patagonicus, by monotypy.
- Brachymyrmex senior synonym of Bryscha: Smith, D.R. 1979: 1424.
- BRACHYPONERA [junior synonym of Pachycondyla]
- Brachyponera Emery, 1900c: 315 [as subgenus of Euponera]. Type-species: Euponera (Brachyponera) croceicornis, by monotypy.
- [Brachyponera also described as new by Emery, 1901a: 43. Type-species not Ponera sennaarensis, unjustified subsequent designation by Emery, 1901a: 43, repeated in Wheeler, W.M. 1911f: 160, Emery, 1911d: 84, Wheeler, W.M. 1922a: 777, Donisthorpe, 1943g: 628, Wilson, 1958d: 346; Bolton, 1973a: 335 and Taylor & Brown, D.R. 1985: 23.]
- Brachyponera as subgenus of Euponera: Emery, 1911d: 83; Wheeler, W.M. 1922a: 649.
- Brachyponera raised to genus: Bingham, 1903: 101; Wilson, 1958d: 346.
- Brachyponera junior synonym of Pachycondyla: Brown, in Bolton, 1994: 164.
- BRYSCHA [junior synonym of Brachymyrmex]
- Bryscha Santschi, 1923b: 652 [as subgenus of Brachymyrmex]. Type-species: Brachymyrmex pilipes, by original designation.
- Bryscha junior synonym of Brachymyrmex: Smith, D.R. 1979: 1424.
- LaPolla, J.S. & Longino, J.T. 2006. An unusual new Brachymyrmex Mayr from Costa Rica, with implications for the phylogeny of the lasiine tribe group. Proceedings of the Entomological Society of Washington. 108:297-305.
- Agosti, D. 1991. Revision of the oriental ant genus Cladomyrma, with an outline of the higher classification of the Formicinae (Hymenoptera: Formicidae). Syst. Entomol. 16: 293-310 (page 296, Brachymyrmex in Formicinae, Pseudolasius genus group)
- Ashmead, W. H. 1905c. A skeleton of a new arrangement of the families, subfamilies, tribes and genera of the ants, or the superfamily Formicoidea. Can. Entomol. 37: 381-384 (page 384, Brachymyrmex in Formicinae, Plagiolepidini)
- Bolton, B. 1994. Identification guide to the ant genera of the world. Cambridge, Mass.: Harvard University Press, 222 pp. (page 50, Brachymyrmex in Formicinae, Brachymyrmecini)
- Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 23, Brachymyrmex in tribe Plagiolepidini)
- Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 174, Brachymyrmex in Camponotinae [Camponotidae])
- Dlussky, G. M.; Fedoseeva, E. B. 1988. Origin and early stages of evolution in ants. Pp. 70-144 in: Ponomarenko, A. G. (ed.) Cretaceous biocenotic crisis and insect evolution. Moskva: Nauka, 232 pp. (page 77, Brachymyrmex incertae sedis in Formicinae)
- do Nascimento, L.E., Amaral, R.R., Ferreira, R.M.dos A., Trindade, D.V.S., do Nascimento, R.E., da Costa, T.S., Souto, R.N.P. 2020. Ants (Hymenoptera: Formicidae) as potential mechanical vectors of pathogenic bacteria in a public hospital in the Eastern Amazon, Brazil. Journal of Medical Entomology 57: 1619–1626. (doi:10.1093/JME/TJAA062).
- Donisthorpe, H. 1943g. A list of the type-species of the genera and subgenera of the Formicidae. [part]. Ann. Mag. Nat. Hist. 11(10): 617-688 (page 628, Brachymyrmex in Formicinae, Dimorphomyrmecini)
- Emery, C. 1895l. Die Gattung Dorylus Fab. und die systematische Eintheilung der Formiciden. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 8: 685-778 (page 771, Brachymyrmex in Camponotinae, Plagiolepidini)
- Emery, C. 1925d. Hymenoptera. Fam. Formicidae. Subfam. Formicinae. Genera Insectorum 183: 1-302 (page 40, Brachymyrmex in Formicinae, Dimorphomyrmecini [subtribe Brachymyrmecini])
- Forel, A. 1878c. Études myrmécologiques en 1878 (première partie) avec l'anatomie du gésier des fourmis. Bull. Soc. Vaudoise Sci. Nat. 15: 337-392 (page 375, Brachymyrmex in Camponotinae [Camponotidae])
- Forel, A. 1893b. Sur la classification de la famille des Formicides, avec remarques synonymiques. Ann. Soc. Entomol. Belg. 37: 161-167 (page 165, Brachymyrmex in Camponotinae, Plagiolepidini)
- Forel, A. 1895b. A fauna das formigas do Brazil. Bol. Mus. Para. Hist. Nat. Ethnogr. 1: 89-139 (page 106, Brachymyrmex in Camponotinae, Plagiolepidini)
- Forel, A. 1899h. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 105-136 (page 123, Brachymyrmex in Camponotinae, Plagiolepidini)
- Forel, A. 1912j. Formicides néotropiques. Part VI. 5me sous-famille Camponotinae Forel. Mém. Soc. Entomol. Belg. 20: 59-92 (page 89, Brachymyrmex in Camponotinae, Myrmelachistini)
- Hölldobler, B.; Wilson, E. O. 1990. The ants. Cambridge, Mass.: Harvard University Press, xii + 732 pp. (page 18, Brachymyrmex in Formicinae, Myrmelachistini)
- Jaffe, K. 1993. El mundo de las hormigas. Baruta, Venezuela: Equinoccio (Ediciones de la Universidad Simón Bolívar), 188 pp. (page 13, Brachymyrmex in Formicinae, Brachymyrmecini)
- Kempf, W. W. 1972b. Catálogo abreviado das formigas da regia~o Neotropical. Stud. Entomol. 15: 3-344 (page 37, Brachymyrmex in Formicinae, Brachymyrmecini)
- Mayr, G. 1868b. Formicidae novae Americanae collectae a Prof. P. de Strobel. Annu. Soc. Nat. Mat. Modena 3: 161-178 (page 163, Brachymyrmex as genus)
- Ortiz, C.M. & Fernández, F. 2014. Brachymyrmex species with tumuliform metathoracic spiracles description of three new species and discussion of dimorphism in the genus (Hymenoptera, Formicidae). ZooKeys 371, 13-33.
- Ortiz-Sepulveda, C.M., Van Bocxlaer, B., Meneses, A.D., Fernández, F. 2019. Molecular and morphological recognition of species boundaries in the neglected ant genus Brachymyrmex (Hymenoptera: Formicidae): toward a taxonomic revision. Organisms Diversity & Evolution (DOI 10.1007/s13127-019-00406-2).
- Santschi, F. 1923b. Revue des fourmis du genre Brachymyrmex Mayr. An. Mus. Nac. Hist. Nat. B. Aires 31: 650-678 (page 652, Subgenera of Brachymyrmex: nominal plus Bryscha. Key to species (out of date))
- Smith, D. R. 1979. Superfamily Formicoidea. Pp. 1323-1467 in: Krombein, K. V., Hurd, P. D., Smith, D. R., Burks, B. D. (eds.) Catalog of Hymenoptera in America north of Mexico. Volume 2. Apocrita (Aculeata). Washington, D.C.: Smithsonian Institution Pr (page 1424, Brachymyrmex senior synonym of Bryscha)
- Wheeler, G. C.; Wheeler, J. 1985b. A simplified conspectus of the Formicidae. Trans. Am. Entomol. Soc. 111: 255-264 (page 258, Brachymyrmex in Formicinae, Brachymyrmecini)
- Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 143, Brachymyrmex in Camponotinae, Plagiolepidini)
- Wheeler, W. M. 1922i. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VII. Keys to the genera and subgenera of ants. Bull. Am. Mus. Nat. Hist. 45: 631-710 (page 697, Brachymyrmex in Formicinae, Myrmelachistini)
- Wheeler, W. M. 1929a. The identity of the ant genera Gesomyrmex Mayr and Dimorphomyrmex Ernest André. Psyche (Camb.) 36: 1-12 (page 12, Brachymyrmex in Formicinae, Brachymyrmecini)
- Wilson, C.M., Smith-Herron, A., Cook, J.L. 2016. Morphology of the male genitalia of Brachymyrmex and their implications in the Formicinae phylogeny. Journal of Hymenoptera Research 50: 81-95 (doi: 10.3897/JHR.50.8697).