Tetramorium dumezi species group

From Bolton (1980)

Diagnosis
Antennae with 12 segments. Sting appendage triangular to pennant-shaped. Mandibles usually smooth and shining with scattered pits but rarely delicately striate (jauresi). Anterior clypeal margin entire except in jauresi-complex where a small impression is present medially. With the head in full-face view the sides are roughly parallel and more or less straight, usually slightly impressed at the eyes but not evenly convex throughout their length. Antennal scrobes feeble or vestigial. Frontal carinae reaching back to occiput except in nodiferum. Scapes short, SI < 90. Propodeum armed with a pair of small teeth or merely angulate, metapleural lobes variable in shape but larger than the propodeal armament. Petiole node in dorsal view usually subglobular, as broad as or slightly broader than long. Sculpture of dorsum of head of longitudinal rugulae which are usually regular; without an occipital rugoreticulum. All dorsal surfaces of head and body with standing hairs and commonly the scapes, tibiae, or both with erect to suberect pilosity or pubescence.

Species Complexes
To some extent this is a convenience-group but it is founded upon a solid core of five closely related species (dumezi-complex) and a pair of species obviously derived from this core (meressei-complex). Also included, however, are the three species referred here to the jauresi-complex which, though sharing many characters with the aforenamed complexes, have an important difference and may be separately derived.

dumezi complex The dumezi-complex is the largest in the group, including candidum, dumezi, elidisum, isipingense and pialtum. In these the anterior clypeal margin is entire, the mandibles are smooth, pilosity on the body is relatively sparse and is usually short and fine, and the postpetiole does not have a high vertical posterior face. In some of the species standing pilosity or pubescence is present on the scapes, tibiae, or both, but is absent in dumezi and pialtum.

jauresi complex The members of the jauresi-complex are separated by their possession of a median impression in the anterior clypeal margin, absent elsewhere in the group. Of the three included species two, qualarum and jauresi, are related, but nodiferum may resemble them by convergence. It is a very specialized form with many derived characters and this tends to obscure its relationships.

meressei complex The two remaining species, meressei and psymanum, form the meressei-complex which closely resembles dumezi and its allies but which have abundant long soft curved acute hairs forming a dense pelt all over the body and on the legs. Apart from this the postpetiole is high, has a narrowly rounded dorsum and has a high vertical free posterior face.