New data on the morphology and distribution of Mesobates forcipatus Thor, 1901, and observations on the systematics of Atractides-like water mites (Acari, Actinedida, Hygrobatidae)

The first record from Southern Europe, and a redescription are given of Mes obates forcipatus, a rare water mite species so far believed to be restrict ed to Scandinavia and Northern Russia. The differences between this species and M. longipes from the Ussuri region in Eastern Russia are outlined. M. churchillensis from Canada is most probably a synonym of M. forcipatus. The phylogenetic significance of some character states in Atractides-like gene ra of the family Hygrobatidae is discussed. A monophyletic origin and early radiation of this group of genera in the Southern hemisphere is hypothesiz ed, with Mesobates and Atractides as two representatives that successively reached the temperate and cold climatic belts of the Northern hemisphere.