Distributional patterns in the Greek species of the terrestrial isopod genus Armadillidium Brandt, 1833

The Mediterranean genus Armadillidium has radiation centres in Italy and Greece, with around 55 species in each of the two countries. Three of the Greek species are found in most parts of the Mediterranean region, and about 40 species are endemic to Greece. Island endemism is, however, low; five species are known from only a single island. Six species occur on several Ionian islands but not on the adjacent mainland. On the Aegean islands, with the exception of Crete, endemic species are lacking. The bulk of the Greek species have restricted distribution ranges on the mainland and the Peloponnese. A gradient of species density from west to east is correlated to climatic factors and a substitution by other conglobating genera in the east.