During the period 1995-1996, 200 specimens of Collembola have been collected in the Bou Hedma National Park, in southern Tunisia, with the aim of studying the influence of mammalian herbivores plant overgrazing on the development of soil mesofauna. They belong to four different species, all of the genus Seira Lubbock, 1869: S. uwei n. sp., S. deserti Jacquemart, 1974, S. dagamae Dallai, 1973 and S. ferrarii Parona, 1888. Seira deserti is a Tunisian species, described from a single specimen. The new description completes the characteristics given in the original description. This species is closely related to S. jacquemarti Barra, 2004 from the mainland Yemen. Seira dagamae, from the Eolic Islands (Italy), is here recorded for the first time outside its region of origin. The Tunisian specimens of Seira ferrarii present the same characteristics as specimens from Italy ; the pigmentation corresponds to the pale form. Seira uwei n. sp. is a species of large size and variable pigmentation. The species shows clear sexual dimorphism, the males having developed pointed setae on the femorae and tibiotarsi of the front legs. This character has also been observed on S. polysperes Barra, 2004 from Yemen.
Collembola, Entomobryidae, Seira, Tunisia, sexual dimorphism, new species.