Tetramorium obesum species group

• Tetramorium antennatum
• Tetramorium brevidentatum
• Tetramorium chepocha
• Tetramorium coonoorense
• Tetramorium decamerum
• Tetramorium indosinense
• Tetramorium lanuginosum
• Tetramorium obesum
• Tetramorium pacificum
• Tetramorium rossi

Based on Bolton 1976, Hita Garcia and Fisher 2011, Agavekar et al. 2017.

Diagnosis

Hita Garcia and Fisher (2011) - 12-segmented antennae; anterior clypeal margin with weak median impression; frontal carinae well-developed, ending between posterior eye margin and posterior head margin, curving down ventrally and forming the posterior scrobe margin; anterior face of mesosoma not developed and mesosomal profile strongly rounded; margination between lateral and dorsal mesosoma present; propodeal spines medium-sized to long and spinose; propodeal lobes triangular and short; petiolar node nodiform; postpetiole roughly rounded; mandibles usually sculptured; cephalic sculpturation well-developed, mostly reticulate-rugose, ground sculpturation of head generally faint or absent; mesosoma and waist segments reticulate-rugose; first gastral tergite unsculptured, smooth, and shiny; all dorsal surfaces with long, erect hairs, usually a mixture of simple and bifid hairs, less commonly including trifid hairs; sting appendage triangular.

Agavekar et al. (2017) - Antennae with 10 or 12 segments; anterior clypeal margin variable, complete or notched, but always unspecialized; eyes of moderate size; antennal scapes usually short to moderately long, not surpassing posterior head margin; antennal scrobes variably developed, from fully absent to strongly developed, deep, and with sharp margins all around; frontal carinae weakly to strongly developed but always surpassing eye level; base of first gastral tergite not concave in dorsal view, without tubercles or teeth on each side; pilosity on dorsal surfaces of body either completely or partly branched, on first gastral tergite usually a mixture of simple and bifid; sting appendage dentiform.

Notes

Agavekar et al. (2017) - The Tetramorium obesum group is distributed in the Indomalayan and Australasian regions, and with currently 11 described species of moderate size. Bolton (1976) recognized two species complexes on the basis of diverging morphology, one of which consists entirely of the five valid species from India.

Additional Resources

• Tetramorium
• Tetramorium species groups

References

• Gaurav Agavekar, G., Hita Garcia, F., Economo, E.P. 2017. Taxonomic overview of the hyperdiverse ant genus Tetramorium Mayr (Hymenoptera, Formicidae) in India with descriptions and X-ray microtomography of two new species from the Andaman Islands. PeerJ 5:e3800 (doi:10.7717/peerj.3800).
• 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 PDF
• Hita Garcia and Fisher. 2011. The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy region – introduction, definition of species groups, and revision of the T. bicarinatum, T. obesum, T. sericeiventre and T. tosii species groups. Zootaxa. 3039: 1-72. dr