Typhlomyrmex

Typhlomyrmex
Typhlomyrmex rogenhoferi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Ectatomminae
Tribe:	Typhlomyrmecini
Genus:	Typhlomyrmex Mayr, 1862
Type species
Typhlomyrmex rogenhoferi
Diversity
7 species (Species Checklist, Species by Country) Typhlomyrmex rogenhoferi Specimen Label

Evolutionary Placement

Ectatomminae Ectatomma   (15 species) Rhytidoponera   (104 species) Gnamptogenys   (144 species) Typhlomyrmex   (7 species)

Based on Brady et al., 2006

A small primarily neotropical genus. Workers are small, have reduced eyes and are rarely sampled. It appears all the species nest and forage within soil or rotting wood.

At a Glance

• Ergatoid queen

 

Identification

Lacau, Villemant & Delabie (2004) - The genus is morphologically homogenous, but there is interspecific variation in petiole shape, head shape, and body size (Brown, 1965; Lacau et al., unpublished data). The terricolous species are the smallest. Bolton (2003: 46) proposed the following potential autapomorphies for the genus: “workers eyes vestigial to absent,” and “male hypopygium with an elongate upcurved and median digitiform process.” The first character has been reported as homoplasic for the entire family by Baroni Urbani et al. (1992): the eye reduction occurs in many other ant genera with hypogaeic habits, in several subfamilies (Hölldobler & Wilson, 1990).

All Typhlomyrmex species share a cryptic ecology and reduced eyes, but it is unknown if this character represents an autapomorphy for the genus in the clade Ectatomminae and/or a convergent adaptation between different Typhlomyrmex species. The digitiform process on the male hypopygium, proposed as autapomorphic by Bolton, is uniformly present in Typhlomyrmex but also occurs in some Gnamptogenys. The digitiform process is possibly homologous in the two taxa (Lacau, unpub.) and should be considered homoplasic. Thus, no clear autapomorphy distinguishes Typhlomyrmex from other ectatommine genera and its position in this subfamily remains unclear.

Keys including this Genus

• Key to Neotropical Ectatomminae genera

 

Keys to Species in this Genus

• Key to Typhlomyrmex workers

Biology

Lacau, Villemant & Delabie (2004) - Compared to other poneromorph genera (sensu Bolton, 2003), Typhlomyrmex biology remains largely unknown but the rare available data reveal a strong ecological diversity between species. Although the distributions of individual species are highly variable, the genus has one of the largest distributions among the New World endemic poneromorph genera (Kempf, 1972). For example, the type species, Typhlomyrmex rogenhoferi which was described from Amazonas State (Brazil), is spread from northern Argentina to southern Mexico (Kempf, 1972; Longino, 1999; Lattke, 2003; Lacau et al., in progress). In contrast, others species have a much more reduced distribution and several are known only from a single locality. Typhlomyrmex meire is only found in a narrow part of the cocoa producing region of southern Bahia (Brazil). Typhlomyrmex prolatus and Typhlomyrmex foreli are two other endemic species respectively described from San Jose (Costa Rica) and Rio Negro (Brazil, Paraná State) regions (Brown, 1965). These restricted geographic ranges must be considered with circumspection owing to the scarcity and the disparity of the data concerning the diversity and the distribution of the Neotropical Formicidae (Kempf, 1972). In fact, ants remain undersampled in large areas of South and Central America. Many species currently regarded as rare or endemic could be relatively common in poorly known regions. This is particularly true for Typhlomyrmex species because they are all cryptobiotic, nesting and foraging within soil or rotting wood. The autoecology of Typhlomyrmex species appears as variable as their distribution. Typhlomyrmex rogenhoferi is an epigaeic species that colonizes large dead trunks lying on the rain forest floor (Lacau et al., 2001), while the others species are subterranean and terricolous. In particular, the small colonies of Typhlomyrmex pusillus nest in minute soil chambers (Brown, 1965; Lacau, pers. obs.); its biological cycle remains almost completely subterranean and only the winged gynes and males periodically emerge for mating.

The genus Typhlomyrmex is generally considered to be rare (Brown, 1965) because these ants are very difficult to find in the field. The terricolous species are rarely collected with extraction traps such as Winkler or Berlese-Tullgren collectors because workers only occasionally forage in the litter (Ward, 2000; Lacau, pers. obs.). Also they are not found in woody macro-elements of litter, such as little branches or dried fruits, nor in logs (see Carvalho & Vasconcelos, 2002; Delabie et al. 1997; Lacau, pers. obs.). The best technique to find living colonies is to look for individuals by careful hand fragmentation of soil elements.

Such laborious field collecting explains the scarcity of Typhlomyrmex specimens in museum collections, especially when compared with those of other poneromorph genera such as Pachycondyla and Hypoponera. Furthermore, the morphology of the different castes is rarely known. For example, Typhlomyrmex prolatus and Typhlomyrmex foreli are only known from their winged queen holotype. In the other taxa, the castes were frequently described separately, from material collected in different localities so that complete series including workers, queens and males coming from the same colony or even from a single location are extremely rare in collections.

Castes

Lacau et al. 2008 reported the existence of both winged and ergatoid queens in one species ("sp. 4").

Morphology

Karyotype

All Karyotype Records for Genus

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Taxon	Haploid	Diploid	Karyotype	Locality	Source	Notes
Typhlomyrmex meire	10	20		Brazil	Mariano et al., 2006b
Typhlomyrmex rogenhoferi		36		French Guiana	Mariano et al., 2006b
Typhlomyrmex rogenhoferi	17	34		Brazil	Mariano et al., 2006b
Typhlomyrmex rogenhoferi	19	38		Brazil	Mariano et al., 2006b

Nomenclature

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

• TYPHLOMYRMEX [Ectatomminae: Typhlomyrmecini]
  • Typhlomyrmex Mayr, 1862: 736. Type-species: Typhlomyrmex rogenhoferi, by monotypy.
  • [Typhlomyrmex Gistel, 1856: 447. Nomen nudum; see Wheeler, W.M. 1911c: 858.]

References

• Bolton, B. 1994. Identification guide to the ant genera of the world. Cambridge, Mass.: Harvard University Press, 222 pp. (page 164, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 176, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• Brown, W. L., Jr. 1965c. Contributions to a reclassification of the Formicidae. IV. Tribe Typhlomyrmecini (Hymenoptera). Psyche (Camb.) 72: 65-78 (page 65, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 16, Typhlomyrmex in Ponerinae)
• 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 79, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• 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 734, Typhlomyrmex in Ponerinae, Ectatommini)
• Emery, C. 1895l. Die Gattung Dorylus Fab. und die systematische Eintheilung der Formiciden. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 8: 685-778 (page 767, Typhlomyrmex in Ponerinae, Ectatommini)
• Emery, C. 1911e. Hymenoptera. Fam. Formicidae. Subfam. Ponerinae. Genera Insectorum 118: 1-125 (page 33, Typhlomyrmex in Ponerinae, Ectatommini [subtribe Typhlomyrmecini])
• Forel, A. 1895b. A fauna das formigas do Brazil. Bol. Mus. Para. Hist. Nat. Ethnogr. 1: 89-139 (page 111, Typhlomyrmex in Ponerinae, Ponerini)
• Forel, A. 1899b. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 1-24 (page 2, Typhlomyrmex in Ponerinae, Ponerini)
• Forel, A. 1917. Cadre synoptique actuel de la faune universelle des fourmis. Bull. Soc. Vaudoise Sci. Nat. 51: 229-253 (page 236, Typhlomyrmex in Ponerinae, Ectatommini)
• Gallardo, A. 1918c. Las hormigas de la República Argentina. Subfamilia Ponerinas. An. Mus. Nac. Hist. Nat. B. Aires 30: 1-112 (page 13, Typhlomyrmex in Ponerinae, Ectatommini)
• Gistel, J. 1856. Die Mysterien der europäischen Insectenwelt. Kempten: Dannheimer, 12 + 532 pp. (page 447, Typhlomyrmex, nomen nudum)
• Hölldobler, B.; Wilson, E. O. 1990. The ants. Cambridge, Mass.: Harvard University Press, xii + 732 pp. (page 10, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• Jaffe, K. 1993. El mundo de las hormigas. Baruta, Venezuela: Equinoccio (Ediciones de la Universidad Simón Bolívar), 188 pp. (page 8, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• Kempf, W. W. 1972b. Catálogo abreviado das formigas da regia~o Neotropical. Stud. Entomol. 15: 3-344 (page 256, Typhlomyrmex in Ponerinae, Typhlomyrmecini)
• Lacau S., Villemant C., Jahyny B., Delabie JHC 2008. Typhlomyrmex Mayr, 1862: un genre méconnu de petites fourmis cryptiques et prédatrices (Ectatomminae: Typhlomyrmecini), pp. 241-283 in Sistemática, biogeografía y conservación de las hormigas cazadoras de Colombia, Editors Jiménez, E., Fernández, F., Arias, T. M. & Lozano-Zambrano, F. H. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, Colombia. 609p.
• Mayr, G. 1862. Myrmecologische Studien. Verh. K-K. Zool.-Bot. Ges. Wien 12: 649-776 (page 714, Typhlomyrmex as genus; Typhlomyrmex in Ponerinae (in key) [Poneridae])
• Mayr, G. 1865. Formicidae. In: Reise der Österreichischen Fregatte "Novara" um die Erde in den Jahren 1857, 1858, 1859. Zoologischer Theil. Bd. II. Abt. 1. Wien: K. Gerold's Sohn, 119 pp. (page 15, Typhlomyrmex in Ponerinae Poneridae])
• Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 135, Typhlomyrmex in Ponerinae, Ectatommini)
• Wheeler, W. M. 1911c. Three formicid names which have been overlooked. Science (N. Y.) (n.s.) 33: 858-860 (page 858, nomen nudum)
• 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 642, Typhlomyrmex in Ponerinae, Ectatommini)