Arion vulgaris (Spanish slug)

The invasiveness of A. vulgaris is related to several factors. Its ability and readiness to colonize humanly-disturbed environments is of major importance. Proschwitz (1997) observed that 99% of Swedish records were from synanthropic habitats and only 1% from natural woodlands. With a proximity to humans, comes the possibility of passive dispersal through trade, particularly in living plants. The garden centre trade and horticulture are particularly implicated (Weidema, 2006). In Poland, there is evidence from studies of molecular diversity that A. vulgaris has originated from repeated, separate introductions from other parts of Europe (Soroka et al., 2007). The ability of A. vulgaris to utilize a great variety of food sources and types has been well-documented and must aid dispersal and colonization. Other than its country of origin (France), it is considered to be invasive across western and central Europe, from the Pyrenees to eastern Poland and from southern France to north Italy, Austria and Slovakia and within an isolated range in eastern Bulgaria.