In southern california, Helix aspersa (Müller), or brown garden snail (BGS), is the most obvious introduced land mollusk. Outdoors, as opposed to a glasshouse environment, BGS occupies the same general habitat as several species of introduced slugs. Native land mollusks seldom invade cultivated areas, preferring undisturbed natural habitats.

John D. Hollen-steiner, Landscape Specialist, State of California Department of Transportation, District 8, and Wendell R. Young, Super vising Biologist, Sun Bernardino County, Department of Agriculture, provided assistance.