Eutetramorium

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Eutetramorium
Eutetramorium mocquerysi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Eutetramorium
Emery, 1899
Type species
Eutetramorium mocquerysi
Diversity
3 species
(Species Checklist)

Eutetramorium mocquerysi casent0005927 profile 1.jpg

Eutetramorium mocquerysi

Eutetramorium mocquerysi casent0005927 dorsal 1.jpg

Specimen Label

Evolutionary Relationships

Rostromyrmex






Cardiocondyla



Ocymyrmex






Nesomyrmex



Xenomyrmex





Terataner




Atopomyrmex



Cataulacus










Carebara



Diplomorium






Melissotarsus



Rhopalomastix






Calyptomyrmex



Tetramorium





Cyphoidris



Dicroaspis










Aretidris



Vollenhovia





Dacetinops



Indomyrma








Crematogaster



Meranoplus






Lophomyrmex




Adlerzia



Recurvidris






Stereomyrmex




Trichomyrmex





Eutetramorium




Royidris




Malagidris



Vitsika








Huberia



Podomyrma





Liomyrmex



Metapone













Kartidris



Mayriella





Tetheamyrma




Dacatria



Proatta









Dilobocondyla



Secostruma






Acanthomyrmex



Myrmecina





Perissomyrmex



Pristomyrmex









some Lordomyrma



Propodilobus





Lasiomyrma




[some Lordomyrma




Ancyridris



some Lordomyrma









Paratopula




Poecilomyrma




Romblonella



Rotastruma








Gauromyrmex



Vombisidris





Temnothorax




Harpagoxenus



Formicoxenus



Leptothorax













Based on Ward et al. (2014) and Blaimer et al. (2018).

Forest dwelling species of ants, the genus is endemic to Madagascar and Comoros.

Identification

One of a number of closely related Myrmicinae genera - the Eutetramorium group - from Madagascar, species in the genus Eutetramorium superficially resemble Tetramorium.

Keys including this Genus

Keys to Species in this Genus

Distribution

World distribution based on political regions. View/Edit Data
Eutetramorium 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

Eutetramorium Species Richness.png

Biology

Castes

Morphology

Worker Morphology

 • Antennal segment count 12 • Antennal club 3 • Palp formula 4,3; 4,2 • Spur formula 1 simple-barbulate, 1 simple-barbulate; 0, 0 • Eyes present • Scrobes absent • Sting present

Male Morphology

 • Antennal segment count 13 • Antennal club 0 • Palp formula 4,3 • Total dental count 7 • Spur formula 1 simple- barbulate, 1 barbulate- pectinate

Nomenclature

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

  • EUTETRAMORIUM [Myrmicinae: Myrmicini]
    • Eutetramorium Emery, 1899f: 280. Type-species: Eutetramorium mocquerysi, by subsequent designation of Wheeler, W.M. 1911f: 163.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Bolton and Fisher (2014):

This small genus was established by Emery (1899) for two conspicuous, large, darkly coloured Madagascan species that superficially resemble Tetramorium. Initially, Emery (1912, 1914) was of the opinion that the genus was referable to the tribe Myrmecinini, but Ashmead (1905) and Wheeler (1910) had already referred it to Tetramoriini, an opinion that Emery (1915b, 1924) also came to accept. Bolton (1976) excluded Eutetramorium from Tetramoriini on morphological grounds, and tentatively transferred it to Myrmicini. This placement persisted until recently, when a molecular analysis of Myrmicini by Jansen & Savolainen (2010) showed that the monophyly of the tribe was dubious, and that Eutetramorium formed a clade with Huberia. The yet unpublished, more detailed, DNA analysis of Myrmicinae by Philip S. Ward has established that Eutetramorium belongs in a strongly supported, endemic Madagascan clade that also includes four other genera.

Worker

Monomorphic myrmicine ants.

Mandible triangular; masticatory margin with 6–8 teeth, longer than the basal margin.

Palp formula 4,3, or 4,2.

Stipes of maxilla with a coarse transverse crest.

Clypeus posteriorly moderately broadly inserted between the frontal lobes; median portion of clypeus broad, not bicari¬nate.

Clypeus with lateral portions raised into a shielding wall or sharp ridge in front of the antennal sockets.

Clypeus with a tooth or triangular point at midpoint of anterior margin; without an unpaired seta at the midpoint.

Frontal carinae restricted to frontal lobes, never extending to the posterior margin of the head.

Antennal scrobes absent.

Antenna with 12 segments, with an apical club of 3 segments; scape distinctly downcurved near its base.

Antennal socket and torulus subtended by a depressed antennal fossa; anterior margin of the fossa is formed by the pos¬terior surface of the narrow, raised, lateral portion of the clypeus.

Torulus with upper lobe concealed by the frontal lobe in full-face view. In profile the torulus lobe large, directed down¬ward over the condyle of the scape.

Eyes present, located slightly in front of, to slightly behind, the midlength of the side of the head capsule in full-face view.

Head capsule without a median, longitudinal carina.

Pronotal humeri rounded in dorsal view.

Metanotal groove impressed.

Propodeum bispinose or bidentate.

Propodeal spiracle behind midlength of sclerite.

Metasternal process present.

Tibial spurs: mesotibia 0 or 1; metatibia 0 or 1; simple when present.

Abdominal segment 4 (first gastral) tergite does not broadly overlap the sternite on the ventral gaster; gastral shoulders absent.

Sting simple, without a spatulate to pennant-shaped lamellate appendage that projects from the dorsum of the shaft near or at its apex.

Main pilosity of dorsal head and body: simple.

Queen

Extreme ergatoid in mocquerysi, alate in monticellii. In parvum a normal dealate queen is present in the type-series, but there is also a specimen that may be an ergatoid or a worker-queen intercaste, or possibly merely an oversized worker, as discussed under parvum. Dealate queen with characters as worker except for the usual modifications of the mesosoma and the presence of ocelli. Venation: see under male.

Male

Known only for E. mocquerysi. Smaller than conspecific worker. Mandible stoutly triangular, with 7 teeth. Palp formula 4,3. Stipital crest present on maxilla. Antenna with 13 segments, filiform. SI 31. First funicular segment short but not globular, about one quarter the length of the second funicular segment. In full-face view eye located in front of midlength of head capsule. Ocelli small, conspicuous. Occipital carina sharp but not forming a raised crest. Mesotibia and metatibia each with a single spur, barbulate on mesotibia, weakly pectinate on metatibia. Notauli weakly present, the anterior arms forming a V-shape. Mesoscutum anteriorly, between the notauli arms, with a longitudinal median carina that is narrowly bifurcated anteriorly. Mesopleuron with a marked transverse sulcus. Propodeum unarmed, the spiracle low on the side and in front of the midlength of the sclerite; propodeal lobes conspicuous, rounded. Petiole with a short, stout anterior peduncle and a short but relatively high node, the spiracle about level with the base of the anterior face of the node. Postpetiole greatly elongated, in profile almost twice the length of the petiole. Subpetiolar process present, small. Cerci present.

Forewing venation (based on male of mocquerysi and queen of monticellii). Rs·f4–5 does not meet R·f3 on anterior margin of wing (= marginal cell open). 2rs-m absent. 1m-cu present. Fusion of Rs+M extended distally, so that 1m-cu arises from Rs+M, not from M. Rs·f3 present (Rs+M divides into Rs·f3 and M·f3–4 proximal of the junction with 2r-rs). A·f2 long, not merely a stub distal of cu-a. In monticellii queens cu-a is retracted toward the wing base and arises from M+Cu, proximal of the point where it divides into M·f1 and Cu·f1–2. However, in the single mocquerysi male examined, cu-a arises at the point where M+Cu divides.

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 383, Eutetramorium in Myrmicinae, Tetramoriini)
  • Bolton, B. 1976. The ant tribe Tetramoriini (Hymenoptera: Formicidae). Constituent genera, review of smaller genera and revision of Triglyphothrix Forel. Bull. Br. Mus. (Nat. Hist.) Entomol. 34: 281-379 (page 293, Noes on genus)
  • Bolton, B. 1994. Identification guide to the ant genera of the world. Cambridge, Mass.: Harvard University Press, 222 pp. (page 106, Eutetramorium in Myrmicinae, Myrmicini)
  • Bolton, B. 1995a. A taxonomic and zoogeographical census of the extant ant taxa (Hymenoptera: Formicidae). J. Nat. Hist. 2 29: 1037-1056 (page 1049, census)
  • Bolton, B. 1995b. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp. (page 190, catalogue)
  • Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 220, Eutetramorium in Myrmicinae, Myrmicini)
  • Bolton, B. & Fisher, B.L. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791:1–99. doi:10.11646/zootaxa.3791.1.1
  • Emery, C. 1899e. Formiche di Madagascar raccolte dal Sig. A. Mocquerys nei pressi della Baia di Antongil (1897-1898). Bull. Soc. Entomol. Ital. 31: 263-290 (page 280, Eutetramorium as genus)
  • Emery, C. 1912b. Études sur les Myrmicinae. [I-IV.]. Ann. Soc. Entomol. Belg. 56: 94-105 (page 105, Eutetramorium in Myrmicinae, Myrmicinini)
  • Emery, C. 1914e. Intorno alla classificazione dei Myrmicinae. Rend. Sess. R. Accad. Sci. Ist. Bologna Cl. Sci. Fis. (n.s.) 18: 29-42 (page 41, Eutetramorium in Myrmicinae, Myrmicinini)
  • Emery, C. 1915g. Noms de sous-genres et de genres proposés pour la sous-famille des Myrmicinae. Modifications à la classification de ce groupe (Hymenoptera Formicidae). Bull. Soc. Entomol. Fr. 1915: 189-192 (page 192, Eutetramorium in Myrmicinae, Tetramoriini)
  • Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 291, diagnosis, catalogue)
  • Forel, A. 1917. Cadre synoptique actuel de la faune universelle des fourmis. Bull. Soc. Vaudoise Sci. Nat. 51: 229-253 (page 245, Eutetramorium in Myrmicinae, Tetramoriini)
  • Kugler, C. 1979b [1978]. Further studies of the myrmicine sting apparatus: Eutetramorium, Oxyopomyrmex, and Terataner (Hymenoptera, Formicidae). Psyche (Camb.) 85: 255-263 (page 225, sting structure)
  • Wheeler, G. C.; Wheeler, J. 1985b. A simplified conspectus of the Formicidae. Trans. Am. Entomol. Soc. 111: 255-264 (page 257, Eutetramorium in Myrmicinae, Tetramoriini (anachronism))
  • Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 141, Eutetramorium in Myrmicinae, Tetramoriini)
  • 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 163, Type-species: Eutetramorium mocquerysi; by subsequent designation)
  • 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 664, Eutetramorium in Myrmicinae, Tetramoriini)
  • Wheeler, W. M. 1922k. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. IX. A synonymic list of the ants of the Malagasy region. Bull. Am. Mus. Nat. Hist. 4 45: 1005-1055 (page 1032, catalogue)