The Spanish Slug (Arion vulgaris) is a snail from the family Slugs, originating in the northern part of the Iberian Peninsula, western France and southern England. Since 1955, plant material and waste has been introduced to a large part of Europe and since 1998 to the USA. In the new premises it is a very unpleasant invasive species of harmful gastropod, which displaces the original species of slugs and does huge damage in agriculture.
The Spanish slug grows to an adult length of 8-12 cm and its color is somewhere between orange and brown. The weight varies between 3-27 g. It is quite similar to a forest slug, which, on average, is lighter and grows larger in size. Significant difference between the two species occurs in the color of young individuals - while the slug are these monochromatic (white or yellowish), small Spanish slugs are brightly colored in shades of yellow to brown with two light stripes on the back.