Tetramorium simillimum

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 : 169

The simillimum -group

Antenna with 12 segments. Sting appendage triangular or dentiform. Mandibles usually sculptured with striation or shagreening, rarely smooth. Anterior clypeal margin entire, without a median notch or impression. Frontal carinae variable, ranging from strong to vestigial but only rarely completely absent. Scrobes with all grades from absent to strong. Antennal scapes with SI <100. Propodeum armed usually with a pair of teeth or tubercles, never with spines, unarmed in one species; the propodeal teeth at most only as long as the metapleural lobes. Middle and hind tibiae without standing hairs of any description but usually with sparse appressed pubescence. Body hairs sparse, all dorsal surfaces with short, stout, blunt hairs, without fine or acute pilosity. Petiole narrowly nodiform in profile, in dorsal view usually as broad as or broader than long. Small to minute species, usually yellow or yellowish brown in colour, rarely otherwise.

This group is based on the Ethiopian region where about 15 species are present. Five species occur in Madagascar, two of which are endemic (p. 155) and one of which is shared with the Ethiopian region. The remaining two species are efficient tramp-forms of African origin which also occur in the New World, and are dealt with here.

Of the two there is no doubt that simillimum is the most successful. It has been widely recorded throughout the tropics and subtropics and also occurs fairly frequently in the temperate zones in zoological and botanical gardens and in conservatories and other constantly heated buildings.