Weeds as a supplementary or alternative food for Arion lusitanicus Mabille(Gastropoda : Stylommatophora)

Susceptibility of 30 weed species to A. lusitanicus feeding was evaluated u nder natural conditions in two successive vegetation seasons (1997-1998). O bservations were conducted on the number and degree of plant injuries, and as a result 13 weed species were found to be most frequently and most heavi ly injured. Food preference of slugs for 10 selected weed species and 8 cul tivated plant species was determined under laboratory conditions. It was fo und that the most frequently and most seriously damaged under field conditi ons was Aegopodium podagraria L. - this and other weeds can be an alternati ve food for the slug. A comparison of the number of seedlings of the studie d species eaten showed a high susceptibility of Galinsoga parviflora Cav., Brassica napus L. and Helianthus annuus L. to slug feeding.