Verbreitung und Habitatpräferenzen der Braunen Wegschnecken in W-Deutschland (Gastropoda: Arionidae: Arion subfuscus s.l.)

Based on the new taxonomic findings on the Arion subfuscus complex, we present data from the mapping survey of Northrhine-Westphalia, mainly originating from between the year 2000 and 18.11.2007 (closing date of this study). Both species show a considerable variability of the color pattern that was photographically documented. The results of our study were ascertained by anatomical determination, that for some individuals was confirmed using molecular methods. The distribution maps are based on 472 records of Arion fuscus and 191 records of Arion subfuscus. Both species were found in Northrhine-Westphalia, as well as in Lower Saxony, Hassiaca and Rhineland-Palatinate. The habitat preferences of Arion fuscus and Arion subfuscus significantly differ: Arion fuscus inhabits open habitats and forests with different soil moisture contents and occurs irrespective of altitude, whereas Arion subfuscus prefers mesic, colline to montaneous (broad-leaved) forests.