Tetramorium bessonii

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Tetramorium bessonii
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Tetramorium
Species: T. bessonii
Binomial name
Tetramorium bessonii
Forel, 1891

Tetramorium bessonii casent0101145 profile 1.jpg

Tetramorium bessonii casent0101145 dorsal 1.jpg

Specimen labels

Tetramorium bessonii is a fairly common species in many arid environments in Madagascar. It can be found in the southeastern and southwestern portions of the island, though it seems completely absent from the southern tip. From these southern localities northwards it is also commonly encountered on the High Plateau, especially in the area around Antananarivo and Moramanga. In the northern part of Madagascar, however, T. bessonii seems to be comparatively rare since it is only known from few localities. It was mostly sampled from anthropogenically modified and grassland habitats followed by spiny forests, thickets, and tropical dry forests, while it was only seldom found in montane or littoral rainforests. The preferred foraging microhabitat is very likely the ground and lower vegetation, and nests are constructed directly in the ground or under rocks. (Hita Garcia and Fisher 2012)

Identification

A member of the Tetramorium bessonii-species group

Hita Garcia and Fisher (2012) - Tetramorium bessonii can be easily distinguished from other species of the group by the following character set: head distinctly longer than wide (CI 92 - 96); petiolar node squamiform and strongly anteroposteriorly compressed with anterodorsal margin situated higher than posterodorsal margin, dorsum tapering backwards posteriorly, in dorsal view strongly transverse (DPeI 209 - 270).

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -17.8873° to -20.775°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.
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Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.
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Biology

Castes

Images from AntWeb

Tetramorium bessonii casent0101277 head 1.jpgTetramorium bessonii casent0101277 profile 1.jpgTetramorium bessonii casent0101277 dorsal 1.jpgTetramorium bessonii casent0101277 label 1.jpg
Worker. Specimen code casent0101277. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MHNG, Geneva, Switzerland.
Tetramorium bessonii casent0101278 head 1.jpgTetramorium bessonii casent0101278 profile 1.jpgTetramorium bessonii casent0101278 dorsal 1.jpgTetramorium bessonii casent0101278 label 1.jpg
Worker. Specimen code casent0101278. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MHNG, Geneva, Switzerland.
Tetramorium bessonii casent0101297 head 1.jpgTetramorium bessonii casent0101297 profile 1.jpgTetramorium bessonii casent0101297 dorsal 1.jpgTetramorium bessonii casent0101297 label 1.jpg
Worker. Specimen code casent0101297. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MHNG, Geneva, Switzerland.
Tetramorium bessonii casent0101298 head 1.jpgTetramorium bessonii casent0101298 profile 1.jpgTetramorium bessonii casent0101298 dorsal 1.jpgTetramorium bessonii casent0101298 label 1.jpg
Worker. Specimen code casent0101298. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MHNG, Geneva, Switzerland.
Tetramorium bessonii casent0101484 head 1.jpgTetramorium bessonii casent0101484 profile 1.jpgTetramorium bessonii casent0101484 dorsal 1.jpgTetramorium bessonii casent0101484 label 1.jpg
Worker. Specimen code casent0101484. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MNHN, Paris, France.
Tetramorium bessonii casent0101744 head 1.jpgTetramorium bessonii casent0101744 profile 1.jpgTetramorium bessonii casent0101744 dorsal 1.jpgTetramorium bessonii casent0101744 label 1.jpg
Holotype of Tetramorium orientaleWorker. Specimen code casent0101744. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by MHNG, Geneva, Switzerland.
Tetramorium bessonii casent0102347 head 1.jpgTetramorium bessonii casent0102347 profile 1.jpgTetramorium bessonii casent0102347 dorsal 1.jpgTetramorium bessonii casent0102347 label 1.jpg
Worker. Specimen code casent0102347. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by NHMUK, London, UK.
Tetramorium bessonii casent0104606 head 1.jpgTetramorium bessonii casent0104606 profile 1.jpgTetramorium bessonii casent0104606 label 1.jpg
Type of Tetramorium bessoniiWorker. Specimen code casent0104606. Photographer April Nobile, uploaded by California Academy of Sciences. Owned by ZMHB, Berlin, Germany.

Nomenclature

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

  • bessonii. Tetramorium (Xiphomyrmex) bessonii Forel, 1891b: 156, pl. 4, fig. 13 (w.) MADAGASCAR. Combination in Xiphomyrmex: Wheeler, W.M. 1922a: 1031; in Tetramorium: Bolton, 1979: 141. See also: Hita Garcia & Fisher, 2012a: 15

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

Description

Worker

Hita Garcia and Fisher (2012) - HL 0.61 - 0.88 (0.81); HW 0.58 - 0.83 (0.76); SL 0.44 - 0.62 (0.58); EL 0.14 - 0.19 (0.17); PH 0.38 - 0.49 (0.45); PW 0.47 - 0.63 (0.58); WL 0.83 - 1.11 (1.03); PSL 0.17 - 0.26 (0.23); PTL 0.10 - 0.14 (0.12); PTH 0.29 - 0.38 (0.34); PTW 0.23 - 0.30 (0.27); PPL 0.21 - 0.29 (0.26); PPH 0.27 - 0.37 (0.32); PPW 0.27 - 0.38 (0.35); CI 92 - 96 (94); SI 73 - 78 (76); OI 21 - 23 (23); LMI 54 - 60 (57); DMI 54 - 60 (57); PSLI 27 - 30 (28); PeNI 42 - 50 (47); LPeI 29 - 39 (34); DPeI 209 - 270 (237); PpNI 57 - 64 (60); LPpI 77 - 84 (80); DPpI 123 - 146 (135); PPI 117 - 135 (127) (15 measured).

Head distinctly longer than wide (CI 92 - 96). Anterior clypeal margin with distinct median impression. Frontal carinae well-developed, ending shortly before posterior head margin. Antennal scrobes faint and weakly developed, posterior and ventral margins never differentiated. Antennal scapes relatively short, not reaching posterior head margin (SI 73 - 78). Eyes small to moderate (OI 21 - 23). Mesosomal outline in profile convex, dorsally transversely rounded, weakly to moderately marginate from lateral to dorsal mesosoma, promesonotal suture generally absent, sometimes present but shallow, metanotal groove weakly developed to absent; mesosoma comparatively stout and high (LMI 54 - 60). Propodeal spines elongate-triangular to spinose, long, and acute (PSLI 27 - 30); propodeal lobes very small and broadly triangular. Petiolar node strongly squamiform and anteroposteriorly compressed, anterior and posterior faces not parallel, anterodorsal margin higher situated and better developed than weaker posterodorsal margin, dorsum tapering backwards posteriorly; node in dorsal view transverse, between 2.1 to 2.7 times wider than long (DPeI 209 - 270), in lateral view more than 2.5 times higher than long (LPeI 29 - 39). Postpetiole in profile rounded and weakly anteroposteriorly compressed, approximately 1.2 to 1.3 times higher than long (LPpI 77 - 84), in dorsal view approximately 1.3 to 1.4 times wider than long (DPpI 123 - 146). Postpetiole in profile more voluminous than petiolar node, in dorsal view approximately 1.2 to 1.3 times wider than petiolar node (PPI 117 - 135). Mandibles generally striate, sometimes weakly sculptured; clypeus always with strong median longitudinal ruga and one or two weaker rugae at each side; cephalic dorsum between frontal carinae with one well-developed longitudinal median ruga and several irregular longitudinal rugae laterally, median ruga diverging approximately at eye level into two rugae running to posterior clypeal margin, rugae fading out shortly before posterior head margin, median ruga of same length as frontal carinae; scrobal area, lateral and ventral head mostly with irregular longitudinal rugulae. Head with faint punctate ground sculpture. Mesosomal dorsum generally unsculptured, rarely with faint traces of rugulae anteriorly, lateral mesosoma anteriorly almost unsculptured, posteriorly irregularly, longitudinally rugulose. Waist segments and gaster unsculptured and smooth. Mesosoma, waist segments, and first gastral tergite moderately shining due to faint punctate or foveolate ground sculpture. All dorsal surfaces of body generally with numerous fine, long, decumbent to erect hairs, and comparatively long appressed to subdecumbent pubescence. Colouration mostly of uniform brownish colour, sometimes gaster darker, often head, legs, and gaster much darker brown than mesosoma and waist segments.

Type Material

Syntype workers, MADAGASCAR, Fianarantsoa, Pays des Betsileo (Besson) (The Natural History Museum: CASENT0102347; Musee d'Histoire Naturelle Genève: CASENT 0101277, CASENT0101278, CASENT0101297, CASENT0101298; Naturhistorisches Museum, Basel: CASENT0101145) [examined].

References

References based on Global Ant Biodiversity Informatics

  • Bolton B. 1979. The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Malagasy region and in the New World. Bulletin of the British Museum (Natural History). Entomology 38:129-181.
  • Fisher B. L. 1997. Biogeography and ecology of the ant fauna of Madagascar (Hymenoptera: Formicidae). Journal of Natural History 31: 269-302.
  • Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.
  • Garcia H. F. and B. L. Fisher. 2012. The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy region—taxonomy of the T. bessonii, T. bonibony, T. dysalum, T. marginatum, T. tsingy, and T. weitzeckeri species groups. Zootaxa 3365: 1-123
  • Rakotonirina J. C. 2010. Survey of leaf litter ant species and assessment of invasive ants in the mining sites at Ambatovy, Madagascar. In Biodiversity, exploration, and conservation of the natural habitats associated with the Ambatovy project, eds. S. M. Goodman & V. Mass. Malagasy Nature, 3: 77-91.
  • Wheeler W. M. 1922. 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. Bulletin of the American Museum of Natural History 45: 1005-1055