Most species of this Palearctic genus are native to the Iberian Peninsula.

non Mabille (= A. vulgaris), which damages agricultural crops and ornamental plants, and A. rufus, a familiar garden pest.

[5] Arion slugs are often transported internationally in shipments of plant products and mushrooms.

[6] Arion slugs have been identified in North America and Australia as invasive species, altering the plants of ecosystems through seed predation and competing with native slugs.

[4][8] Species include: The name Arion is in reference to Aelion's De Natura Animalium, which features a story about areíones - snails which leave their shells behind to feed, thus outsmarting predators who attack the empty shells.