Tetramorium kelleri Forel

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, pp. 129-181 : 145

Tetramorium kelleri Forel

(Fig. 13)

Tetramorium {Xiphomyrmex) kelleri Forel, 1887: 385 . Syntype workers, Madagascar: nr Tamatave, bois de l'lvondro (C. Keller) (MHN, Geneva; BMNH; MCZ, Cambridge; USNM, Washington) [examined].

Worker. TL 4.9 - 5.3, HL 1.06 - 1.16, HW 0.90 - 0.98, CI 83 - 86, SL 0.84 - 0.94, SI 93 - 97, PW 0.72 - 0.82, AL 1.34 - 1.42 (8 measured).

Mandibles striate, median clypeal carina distinct. Frontal carinae strong, extended back nearly to the occipital margin and only very feebly curved so that they are roughly parallel throughout their length. Antennal scrobe a well-marked groove capable of holding the scape. Pronotal corners rounded in dorsal view. Metanotal groove absent to very weakly marked with the alitrunk in profile. Propodeal spines long and acute, the metapleural lobes low and rounded. Petiole in profile with the anterior and dorsal surfaces confluent through a broad curve or an extremely obtuse angle, the dorsum ascending posteriorly so that the anterior face of the node is distinctly shorter than the posterior. In dorsal view the petiole node much longer than broad. Head and dorsal alitrunk reticulate-rugose, the dorsal surfaces of the pedicel also rugose but here the rugae are longitudinal and are more strongly developed on the petiole than on the postpetiole. Gaster unsculptured. All dorsal surfaces of head and body with dense, long, fine hairs which are erect or suberect, and some of which are very long. Antennal scapes and legs also with abundant long, erect hairs, the longest on the scapes being almost or quite twice as long as the maximum scape width. Colour orange-brown.

Probably the most distinctive species of its group in the Malagasy region, the combination of large size, light colour, extreme hairiness and characteristic node shape makes kelleri immediately recognizable. Its nearest relatives do not appear to be any of the Malagasy species but rather it is closest related to pilosum Emery and yerburyi Forel of the Oriental region.