Myrmoteras

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Myrmoteras
Myrmoteras indicum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Myrmoteratini
Genus: Myrmoteras
Forel, 1893
Type species
Myrmoteras binghamii
Subgenera
Diversity
41 species
(Species Checklist)

Myrmoteras indicum casent0102131 profile 1.jpg

Myrmoteras indicum

Myrmoteras indicum casent0102131 dorsal 1.jpg

Specimen Label

Evolutionary Relationships
Formicinae

Myrmelachistini
  (2 genera)




Lasiini
  (9 genera)




Melophorini
  (9 genera)




Formicini
  (8 genera)





Gesomyrmex, Oecophylla



Plagiolepidini
  (10 genera)







Gigantiops
  (1 species)



Santschiella
  (1 species)





Myrmoteras
  (41 species)



Camponotini
  (8 genera)










Based on Ward et al. 2016.

Myrmoteras is unique among the Formicinae in having the mandibles specialized as trap-jaws. This feature has evolved independently several times in ants and is also found in the ponerines Odontomachus and Anochetus, as well as a number of myrmicine genera. Species are found largely in forested areas where they forage singly on the surface of the ground and in leaf litter. Nests are small, with a single queen and a handful of workers, often in small twigs on the ground. These ants are relatively rare, or at least uncommonly encountered. The genus is primarily Oriental, occurring from India to the Philippines, Sulawesi and Lombok but is especially rich in Borneo and Sulawesi.

At a Glance • Trap-Jaw  
 

Photo Gallery

  • Myrmoteras worker with her mandibles in their feeding position. Photo by Kalesh Sadasivan.
  • Myrmoteras worker from Danum Valley, Sabah, Malaysia.
  • Myrmoteras worker from Danum Valley, Sabah, Malaysia. The trigger hair, used to release the mandibles from their open to closed position, can be seen between the mandibles.

Identification

Keys to Species in this Genus

Distribution

Primarily an Oriental distribution from India to the Philippines, Sulawesi, and Lombok of the Lesser Sunda Islands; limited to the east by Weber’s Line (Zettel and Sorger 2011).

China, India, Sri Lanka, Borneo, Indonesia, Philippines World distribution based on political regions. View/Edit Data
Myrmoteras 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

Myrmoteras Species Richness.png

Biology

Species of the genus Myrmoteras Forel, 1893 are among the most bizarre ant forms and unique among Formicinae by having mandibles that form into a specialized trap-jaw mechanism – a character that, however, has convergently evolved in other subfamilies (Odontomachus and Anochetus in Ponerinae; Dacetini in Myrmicinae). The small Myrmoteras ants with cryptic living habits in leaf litter have been rarely collected in the past, although more specialized collecting methods have yielded a relatively high species diversity, especially on Borneo and Sulawesi (Agosti 1992).

Castes

Queen-worker dimorphism in body size is exceedingly small, and so is ovarian dimorphism (4 vs. 2 ovarioles). Flight thorax of queens has a large pronotum (dorsum of first segment), indicating worker-like neck muscles, hence queens are able to hunt during independent foundation (non-claustral ICF).


Laboratory nest of Myrmoteras from Chiangmai province, Thailand. Dealate queen (red arrow) is almost the same size as her daughter workers. Photo by Christian Peeters.

Morphology

Worker Morphology

 • Antennal segment count 12 • Antennal club absent-gradual weak • Palp formula 6,4; 5,4; 5,5; 4,3; 4,2; 3,3 • Total dental count 8-16 • Spur formula 1 simple, 1 simple; 0, 0 • Eyes present • Scrobes absent • Sting absent

Male Morphology

 • Antennal segment count 13 • Antennal club 0 • Palp formula 6,4; 3,3 • Total dental count 0 • Spur formula 1 simple, 1 simple

Nomenclature

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

Bui et al 2013 - Myrmoteras is in the tribe Myrmoteratini Emery, 1895 (Bolton, 2003). Its geographical range is the Oriental region and the Austro-Malayan subregion of the Australian region (Moffett, 1985; Xu, 1998; Agosti, 1992; Zettel & Sorger, 2011). Creighton (1930) revised the genus for the first time, listing six species including two new species. Moffett (1985) recognised a total of 18 species including 10 new species in two morphologically distinct subgenera: Myrmoteras with seven species and the new subgenus Myagroteras with eleven species. Later Agosti (1992) revised the species in the Malay archipelago including the Malay peninsula south of the Kra isthmus, the Philippines, New Guinea, the Islands of New Britain and New Ireland, and added 13 new species. Xu (1998) described one new species from Yunnan province, southwestern China, and recently Zettel & Sorger (2011) revised the Philippine taxa, adding 2 new species, and gave a list of 34 valid species names from the whole range of the genus.

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 295, Myrmoteras in Formicinae, Oecophylla genus group)
  • Agosti, D. 1992. Revision of the ant genus Myrmoteras of the Malay Archipelago (Hymenoptera, Formicidae). Rev. Suisse Zool. 99: 405-429 PDF(page 405, Revision of genus)
  • 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, Myrmoteras in Gesomyrmicinae, Myrmoteratini)
  • Bingham, 1903: 313 (diagnosis); Emery, 1925b: 36 (diagnosis, catalogue); Creighton, 1930a: 184 (all species key); Wheeler, W.M. 1933e: 75 (all species key); Chapman & Capco, 1951: 209 (Asia checklist); Gregg, 1954: 25 (all species key); Moffett, 1985b: 17 (diagnosis, all species revision, key); Dlussky & Fedoseeva, 1988: 77 (synoptic classification); Agosti, 1992: 405 (diagnosis, review of genus, Malesian species key); Bolton, 1994: 51 (synoptic classification); Bolton, 1995a: 1051 (census); Bolton, 1995b: 287 (catalogue); Bolton, 2003: 23, 107 (diagnosis, synopsis).
  • Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 107, Myrmoteras in Formicinae, Myrmoteratini)
  • Emery, C. 1895l. Die Gattung Dorylus Fab. und die systematische Eintheilung der Formiciden. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 8: 685-778 (page 772, Myrmoteras in Camponotinae, Myrmoteratini)
  • Emery, C. 1925d. Hymenoptera. Fam. Formicidae. Subfam. Formicinae. Genera Insectorum 183: 1-302 (page 36, Myrmoteras in Formicinae, Myrmoteratini)
  • Forel, A. 1893i. Note préventive sur un nouveau genre et une nouvelle espèce de Formicide (Camponotide). Ann. Soc. Entomol. Belg. 37: 607-608 (page 607, Type-species: Myrmoteras binghamii, by monotypy)
  • Forel, A. 1894c. Les Formicides de l'Empire des Indes et de Ceylan. Part IV. J. Bombay Nat. Hist. Soc. 8: 396-420 (page 418,420: Myrmoteras described as new)
  • Forel, A. 1917. Cadre synoptique actuel de la faune universelle des fourmis. Bull. Soc. Vaudoise Sci. Nat. 51: 229-253 (page 248, Myrmoteras in Camponotinae, Myrmoteratini)
  • Ito F., Miyazaki S. Hashim R. & Billen J. 2017. Colony composition and behavioral characteristics of Myrmoteras iriodum and M. jaitrongi in Ulu Gombak, Peninsular Malaysia (Hymenoptera: Formicidae). Asian Myrmecology 9: e009010 (1-9). DOI: 10.20362/am.009010
  • Moffett, M.W. 1985. Revision of the genus Myrmoteras. Bulletin of the Museum of Comparative Zoology 151: 1-53. [1](page 1, Revision of genus)
  • Moffett MW, 1986. Trap-jaw predation and other observations on two species of Myrmoteras (Hymenoptera: Formicidae). Insectes Sociaux 33: 85 – 99.
  • Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 143, Myrmoteras in Camponotinae, Myrmoteratini)
  • 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 694, Myrmoteras in Formicinae, Myrmoteratini)
  • Zettel, H. and Sorger, D.M. 2011. New Myrmoteras ants from the southeastern Philippines. Raffles Bulletin of Zoology. 59:61-67. PDF