Rareness of certain Mediterranean ant species: fact or artifact?

A checklist of the ants recorded during five years in a small urban area (400 m2) in Sant Cugat (Barcelona, Spain) is presented. 23 species nest in the area, 7 species (hypogaeic or parasitic) probably nest and 5 species nest in the vicinity; five additional species have also been recovered from the area. The rarity of some of these (Leptanilla sp., Hypoponera abeillei (Emery), Cryptopone ochraceum (Mayr), Smithistruma tenuipilis (Emery), Epitritus argiolus Emery, Trichoscapa membranifera Emery, Chalepoxenus muellerianus (Finzi), Anergates atratulus (Schenck), Plagiolepis xene (Schenck), Lasius carniolicus Mayr) and the high number of species suggest that a) rarity in Mediterranean ant species may be explained by the insufficient sampling in time of adequate microhabitats (hypogaeic species) or by the inconspicuousness of social parasitic species, and b) that previously published species lists of ants from Mediterranean habitats might be rather incomplete. © 1991 Birkhäuser Verlag.