Porcellionides pruinosus and Porcellio scaber
Older shot with two species together under one roof tile: Porcellionides pruinosus (bottom) with an older and a younger Porcellio scaber. Woodlice keep on growing all their life, so sizes are hard to compare, but this is fairly representative of size differences between the two, although both the Porcellionides and the larger Porcellio scaber in this image would still have some growth left in them.
''Porcellionides pruinosus'' is a cosmopolitan woodlouse that is native to Europe, and is suspected to consist of very closely related species. Ten subspecies are recognised. The species carries ''Wolbachia'' endosymbionts, which is an alpha-proteobacterium that is known to modify the reproduction of their crustacean hosts by inducing cytoplasmic incompatibility or feminisation.