The white garden snail (Theba pisana), sometimes known as the Italian white snail, can be a serious pest of landscape ornamentals, including trees, shrubs, groundcovers, and herbaceous plants (Figure 1). Although it has been established in California for at least 100 years, it has mostly been inactive but has recently become more active in southern California and in coastal San Mateo County. If this activity continues to increase, the white garden snail will become a major pest and do serious harm to landscape plants, especially in coastal California.