.jpg){kind=logo}
Trachymyrmex
| Trachymyrmex | |
|---|---|
| |
| Trachymyrmex septentrionalis | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Subfamily: | Myrmicinae |
| Tribe: | Attini |
| Genus: | Trachymyrmex Forel, 1893 |
| Type species | |
| Atta septentrionalis, now Trachymyrmex septentrionalis | |
| Diversity | |
| 9 species (Species Checklist, Species by Country)
| |
A genus of fungus growing ants. Trachymyrmex is mostly Neotropical, occurring in the Nearctic region mostly in the southern parts of Florida, Texas and Arizona, except for one species. Trachymyrmex septentrionalis that occurs up to New York in the North, Illinois, Texas, and Louisiana in the west, and south to Florida and the West Indies. Long Island and Staten Island in New York are the northernmost records for an attine ant. (Mayhé-Nunes & Brandão 2002)
| At a Glance | • Fungus Grower |
Identification
Santos et al. (2025):
- Median pronotal spines separated (Fig. 2, B), if basally fused, then their apexes are considerably distant from each other [e.g. Trachymyrmex arizonensis (Wheeler, 1907)].
- Mandible dorsum striated (Fig. 2, E).
- Preocular carinae short, frequently curved towards the frontal carinae (Fig. 2, B).
- Pilosity sparse (Fig. 2, G).
- Postocular protuberance inconspicuous (Fig. 2, B).
- Vertexal corners slightly rounded (Fig. 2, E).
- Posterior margin of head with mild median impression (Fig. 2, B).
- Postpetiole in lateral view with posteromedial impression (posterior margin concave) (Fig. 2, G, I).
- First gastral tergite generally with inconspicuous pairs of lateral and median ridges (Fig. 2, I).
- Propodeal projections spiny (Fig. 2, G), rarely blunt [e.g. Trachymyrmex desertorum (Wheeler, 1911)].
- Promesonotum with subequal-sized projections (Fig. 2, G).
- Antennal scape never with basal lobe; microtubercles tiny (Fig. 2, B, E).
Santos et al. (2025), Fig. 2. Comparison between Mycetomoellerius, Paratrachymyrmex and Trachymyrmex species. A, M. oetkeri (UFV-LABECOL-005130); B, T. septentrionalis (ANTWEB1060085); C, M. kempfi (CASENT0178107); D, M. turrifex (CASENT0104760); E, P. bugnioni (CASENT0919968); F, M. mesopleuralis (MZSPHYM0136546); G, T. septentrionalis (CASENT0919975); H, M. kempfi (CASENT0178107); I, T. pakawa (CASENT0919984); J, P. intermedius (CASENT0919970); K, M. holmgreni (CASENT0178106). Black arrowheads, median pronotal spines basally fused; Red arrowheads, median pronotal spines separated; Blue arrowheads, pair of lateral ridges on first gastral tergite; Grey arrowheads, pair of median ridges on first gastral tergite. Abbreviations: frc, frontal carinae; lpsp, lateral pronotal spines; mdl, mandibles; mets, metanotal suture; mspl, mesopleura; phi, posterior margin of head impression; pmsnt, promesonotum ; popr, postocular protuberance; ppet, postpetiole; proc, preocular carinae; prs, pronotal spines; pvmh, posterior section of ventral margin of head; scp, scape; vc, vertexal corners; tgI, first tergum of the gaster.
,_Fig._2.jpg)
|
See images of species within this genus |
Keys including this Genus
Keys to Species in this Genus
Distribution
Distribution and Richness based on AntMaps
Species by Region
Number of species within biogeographic regions, along with the total number of species for each region.
| Afrotropical Region | Australasian Region | Indo-Australian Region | Malagasy Region | Nearctic Region | Neotropical Region | Oriental Region | Palaearctic Region | |
|---|---|---|---|---|---|---|---|---|
| Species | 0 | 0 | 0 | 0 | 7 | 7 | 0 | 0 |
| Total Species | 2841 | 1736 | 3045 | 932 | 835 | 4379 | 1741 | 2862 |
Biology
Association with Other Organisms
Explore: Show all Associate data or Search these data. See also a list of all data tables or learn how data is managed.
Species Uncertain
An unknown species of Trachymyrmex is a host for the diapriid wasp Mimopriella sp. (www.diapriid.org).
All Associate Records for Genus
Click here to show/hide associate data.
Life History Traits
- Mean colony size: >100 to well over 1000 (Greer et al., 2021)
- Compound colony type: not parasitic (Greer et al., 2021)
- Nest site: hypogaeic (Greer et al., 2021)
- Diet class: herbivore (Greer et al., 2021)
- Foraging stratum: subterranean/leaf litter (Greer et al., 2021)
- Foraging behaviour: cooperative (Greer et al., 2021)
Castes
Morphology
Worker Morphology
- Explore: Show all Worker Morphology data or Search these data. See also a list of all data tables or learn how data is managed.
• Antennal segment count: 11 • Antennal club: gradual-3 weak • Palp formula: 4,2 • Total dental count: 8-12 • Spur formula: 0, 0 • Eyes: 11-100 ommatidia • Scrobes: weakly developed • Pronotal Spines: dentiform • Mesonotal Spines: dentiform • Propodeal Spines: dentiform; present • Petiolar Spines: absent; dentiform • Caste: polymorphic • Sting: NA • Metaplural Gland: present • Cocoon: absent
Male Morphology
- Explore: Show all Male Morphology data or Search these data. See also a list of all data tables or learn how data is managed.
• Antennal segment count 13 • Antennal club gradual-4 weak • Palp formula 4,2 • Total dental count 3-7 • Spur formula 0,0
Karyotype
Species Uncertain
The generic placement of the following species is uncertain. Species formerly placed in Trachymyrmex are now placed within Trachymyrmex, Mycetomoellerius and Paratrachymyrmex.
- “Trachymyrmex” sp. 1, 2n=12 (n=6), karyotype=12M, Panama, Murakami et al. (1998).
- “Trachymyrmex” sp. 2, 2n=18 (n=9), karyotype=18M, Panama, Murakami et al. (1998).
- “Trachymyrmex” sp. 3, 2n=22 (n=11), karyotype=18M + 4SM, Brazil, Barros et al. (2013).
All Karyotype Records for Genus
- See additional details at the Ant Chromosome Database.
- Explore: Show all Karyotype data or Search these data. See also a list of all data tables or learn how data is managed.
Click here to show/hide karyotype data.
Phylogeny
| Myrmicinae |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
See Phylogeny of Myrmicinae for details.
Nomenclature
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- TRACHYMYRMEX [Myrmicinae: Attini]
- Trachymyrmex Forel, 1893e: 600 [as subgenus of Atta]. Type-species: Atta septentrionalis, by subsequent designation of Wheeler, W.M. 1911f: 174.
- Trachymyrmex subgenus of Cyphomyrmex: Emery, 1913b: 251; Emery, 1924d: 344.
- Trachymyrmex subgenus of Acromyrmex: Forel, 1917: 247.
- Trachymyrmex raised to genus: Gallardo, 1916b: 242; Wheeler, W.M. 1916c: 11; Wheeler, W.M. 1922a: 669; Borgmeier, 1950b: 384; Kempf, 1972a: 252.
Taxonomic Notes
Kempf was in the process of revising Trachymyrmex at the time of his death. Brandao and Mayhe-Nunes subsequently used Kemp's manuscripts when revising the genus in a series of papers that focused on individual species groups.
Description
Worker
Mayhé-Nunes & Brandão (2002) - Dorsal mesosomal spines multidentate or multituberculate, often transformed into small blunt hillocks, bristling with secondary tubercles. Frontal carinae strongly diverging caudad reaching or nearly reaching the lateral angles of the occiput, forming laterad a sometimes shallow but always present scrobe for part of the scapes. Inter frontal width close to or less than 2/3 of the head Width (including eyes). Worker caste monomorphic or nearly so, size Variation slight; major workers absent.
References
- 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, Trachymyrmex in Cryptoceridae, Attinae)
- Barden, P. 2017. Fossil ants (Hymenoptera: Formicidae): ancient diversity and the rise of modern lineages. Myrmecological News 24: 1-30.
- Barrera, C.A., Sosa-Calvo, J., Schultz, T.R., Rabeling, C., Bacci, M., Jr 2021. Phylogenomic reconstruction reveals new insights into the evolution and biogeography of Atta leaf-cutting ants (Hymenoptera: Formicidae). Systematic Entomology 47: 13-35 (doi:10.1111/syen.12513).
- Barros, L.A.C., Mariano, C.S.F., Pompolo, S.G. 2013. Cytogenetic studies of five taxa of the tribe Attini (Formicidae: Myrmicinae). Caryologia 66: 59–64 (Template:Doi.org)).
- Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 201, Trachymyrmex as genus)
- Borgmeier, T. 1923. Catalogo systematico e synonymico das formigas do Brasil. 1 parte. Subfam. Dorylinae, Cerapachyinae, Ponerinae, Dolichoderinae. Arch. Mus. Nac. (Rio J.) 24: 33-103 (page 128, Trachymyrmex as genus)
- Borgmeier, T. 1950b. Bemerkungen zu Dr. Creighton's Werk "The ants of North America". Rev. Entomol. (Rio J.) 21: 381-386 (page 384, Trachymyrmex as genus)
- Boudinot, B.E. 2019. Hormigas de Colombia. Cap. 15. Clave para las subfamilias y generos basada en machos. Pp. 487-499 in: Fernández, F., Guerrero, R.J., Delsinne, T. (eds.) 2019d. Hormigas de Colombia. Bogotá: Universidad Nacional de Colombia, 1198 pp.
- Burchill, A.T., Moreau, C.S. 2016. Colony size evolution in ants: macroevolutionary trends. Insectes Sociaux 63, 291–298 (doi:10.1007/s00040-016-0465-3).
- Cantone S. 2018. Winged Ants, The queen. Dichotomous key to genera of winged female ants in the World. The Wings of Ants: morphological and systematic relationships (self-published).
- Dahan, R.A., Grove, N.K., Bollazzi, M., Gerstner, B.P., Rabeling, C. 2021. Decoupled evolution of mating biology and social structure in Acromyrmex leaf-cutting ants. Behavioral Ecology and Sociobiology 76, 7 (doi:10.1007/s00265-021-03113-1).
- de Bekker, C., Will, I., Das, B., Adams, R.M.M. 2018. The ants (Hymenoptera: Formicidae) and their parasites: effects of parasitic manipulations and host responses on ant behavioral ecology. Myrmecological News 28: 1-24 (doi:10.25849/myrmecol.news_028:001).
- Donisthorpe, H. 1943h. A list of the type-species of the genera and subgenera of the Formicidae. [concl.]. Ann. Mag. Nat. Hist. 11(10): 721-737 (page 733, Trachymyrmex subgenus of Cyphomyrmex)
- Emery, C. 1895l. Die Gattung Dorylus Fab. und die systematische Eintheilung der Formiciden. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 8: 685-778 (page 770, Trachymyrmex in Myrmicinae, Attini; Trachymyrmex as subgenus of Atta)
- Emery, C. 1913c. Études sur les Myrmicinae. [V-VII.]. Ann. Soc. Entomol. Belg. 57: 250-262 (page 251, Trachymyrmex subgenus of Cyphomyrmex; Trachymyrmex in Myrmicinae, Attini)
- Emery, C. 1922c. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [part]. Genera Insectorum 174B: 95-206 (page 344, Trachymyrmex subgenus of Cyphomyrmex; Trachymyrmex in Myrmicinae, Attini)
- Fernandez, F., Guerrero, R.J., Sánchez-Restrepo, A.F. 2021. Sistemática y diversidad de las hormigas neotropicales. Revista Colombiana de Entomología 47, 1–20 (doi:10.25100/socolen.v47i1.11082).
- Forel, A. 1893h. Note sur les Attini. Ann. Soc. Entomol. Belg. 37: 586-607 (page 600, Trachymyrmex as subgenus of Atta)
- Forel, A. 1899d. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 25-56 (page 30, Trachymyrmex as subgenus of Atta)
- Forel, A. 1917. Cadre synoptique actuel de la faune universelle des fourmis. Bull. Soc. Vaudoise Sci. Nat. 51: 229-253 (page 247, Trachymyrmex subgenus of Acromyrmex; Trachymyrmex in Myrmicinae, Attini)
- Gallardo, A. 1916c. Notas acerca de la hormiga Trachymyrmex pruinosus Emery. An. Mus. Nac. Hist. Nat. B. Aires 28: 241-252 (page 242, Trachymyrmex raised to genus)
- Gallardo, A. 1916e. Notes systématiques et éthologiques sur les fourmis attines de la République Argentine. An. Mus. Nac. Hist. Nat. B. Aires 28: 317-344 (page 318, Trachymyrmex as genus)
- Hanisch, P.E., Sosa-Calvo, J., Schultz, T.R. 2022. The last piece of the puzzle? Phylogenetic position and natural history of the monotypic fungus-farming ant genus Paramycetophylax (Formicidae: Attini). Insect Systematics and Diversity 6 (1): 11:1-17 (doi:10.1093/isd/ixab029).
- Jansen, G., Savolainen, R. 2010. Molecular phylogeny of the ant tribe Myrmicini (Hymenoptera: Formicidae). Zoological Journal of the Linnean Society 160(3), 482–495 (doi:10.1111/j.1096-3642.2009.00604.x).
- Kaspari, M., Pickering, J., Longino, J., Windsor, D. 2001. The phenology of a Neotropical ant assemblage: evidence for continuous and overlapping reproduction. Behavioral Ecology and Sociobiology 50, 382–390 (doi:10.1007/s002650100378).
- Kempf, W. W. 1972b. Catálogo abreviado das formigas da regia~o Neotropical. Stud. Entomol. 15: 3-344 (page 252, Trachymyrmex as genus)
- Kusnezov, N. 1964 [1963]. Zoogeografía de las hormigas en Sudamérica. Acta Zool. Lilloana 19: 25-186 (page 63, Trachymyrmex as genus)
- Mayhé-Nunes, A. J. and Brandão, C. 2002. Revisionary studies on the attine ant genus Trachymyrmex Forel. Part 1: definition of the genus and the opulentus group (Hymenoptera: Formicidae). Sociobiology. 40:667-698.
- Mayhé-Nunes, A. J. and Brandão, C. R. F. 2005. Revisionary studies on the attine ant genus Trachymyrmex Forel. Part 2: the Iheringi group (Hymenoptera: Formicidae). Sociobiology. 45(2):271-305.
- Mayhé-Nunes, A.J., Brandão, C.R.F. 2007. Revisionary studies on the attine ant genus Trachymyrmex Forel. Part 3: The Jamaicensis group (Hymenoptera: Formicidae). Zootaxa. 1444:1-21 (doi:10.11646/zootaxa.1444.1.1).
- Mueller, U.G., Schultz, T.R., Currie, C.R., Adams, R.M.M., Malloch, D. 2001. The origin of the attine ant-fungus mutualism. The Quarterly Review of Biology 76, 169-197.
- Murakami, T., Fujiwara, A., Yoshida, M.C. 1998. Cytogenetics of ten ant species of the tribe Attini (Hymenoptera, Formicidae) in Barro Colorado Island, Panama. Chromosome Science 2: 135–139.
- Rabeling C, Cover SP, Mueller UG & Johnson RA. 2007. A review of the North American species of the fungus-gardening ant genus Trachymyrmex (Hymenoptera: Formicidae). Zootaxa 1664:1-54.
- Solomon, S.E., Rabeling, C., Sosa-Calvo, J., Lopes, C.T., Rodrigues, A., Vasconcelos, H.L., Bacci Jr, M., Mueller, U.G., Schultz, T.R. 2019. The molecular phylogenetics of Trachymyrmex Forel ants and their fungal cultivars provide insights into the origin and coevolutionary history of ‘higher-attine’ ant agriculture. Systematic Entomology 44: 939-956 (doi:10.1111/syen.12370).
- Wheeler, W. M. 1907d. The fungus-growing ants of North America. Bull. Am. Mus. Nat. Hist. 23: 669-807 (page 670, Trachymyrmex as subgenus of Atta)
- Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 141, Trachymyrmex as subgenus of Atta)
- Wheeler, W. M. 1911g. A list of the type species of the genera and subgenera of Formicidae. Ann. N. Y. Acad. Sci. 21: 157-175 (page 174, Type-species: Atta septentrionalis, by subsequent designation)
- Wheeler, W. M. 1916c. Ants collected in British Guiana by the expedition of the American Museum of Natural History during 1911. Bull. Am. Mus. Nat. Hist. 35: 1-14 (page 11, Trachymyrmex as genus)
- 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 669, Trachymyrmex as genus; Trachymyrmex in Myrmicinae, Attini)