Brachymyrmex

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Brachymyrmex
Brachymyrmex patagonicus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Myrmelachistini
Genus: Brachymyrmex
Mayr, 1868
Type species
Brachymyrmex patagonicus
Diversity
61 species
(Species Checklist)

Brachymyrmex patagonicus casent0173480 profile 1.jpg

Brachymyrmex patagonicus

Brachymyrmex patagonicus casent0173480 dorsal 1.jpg

Specimen Label

Synonyms
Evolutionary Relationships
Formicinae
Myrmelachistini

Brachymyrmex
  (61 species)



Myrmelachista
  (69 species)





Lasiini
  (9 genera)




Melophorini
  (9 genera)




Formicini
  (8 genera)





Gesomyrmex, Oecophylla



Plagiolepidini
  (10 genera)





Gigantiops, Myrmoteras, Santschiella



Camponotini
  (8 genera)








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, 61 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).

Identification

Small workers with a 9-segmented antennae that lacks an antennal club.

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.

Keys including this Genus

Keys to Species in this Genus

Distribution

World distribution based on political regions. View/Edit Data
Brachymyrmex Distribution.png Worlddistribution legend.jpg

Species richness

Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data

Brachymyrmex Species Richness.png

Biology

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.

Castes

Most species monomorphic, with two dimorphic species Brachymyrmex pilipes and Brachymyrmex micromegas.

Morphology

Worker Morphology

 • Antennal segment count 9 • Antennal club absent-gradual, weak • Palp formula 6,4 • Spur formula 0, 0 • Eyes present • Scrobes absent • Sting absent

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • 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.

References

  • 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)
  • 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)
  • 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. PDF
  • 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.
  • 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).