Snails

Pestgon FactSheet

SNAILS (Helix aspersa)

Description:
Introduced from France during the 1850s for use as food, the Brown Garden Snail is the most common snail causing problems in southern California landscapes. As a pest, snails and slugs are among the most bothersome pests in the commercial landscape. Both are of the mollusk phylum. The brown garden snail is about 1 inch in diameter at maturity and has a distinct color pattern. The shell of the garden snail is light brown with dark brown bands following the spiral of the shell. Colorations can vary from pale yellow to almost black. Snails and slugs move by gliding along on a muscular foot. This muscle constantly secretes mucus, which later dries to form the silvery slime trail that indicates the presence of either pest.

Biology:
Snails are most active during the night and early morning when it is damp. They are also active on cloudy or foggy days. In southern California, particularly along the coast, young snails are active throughout the year. Irrigated, commercial, landscapes allow them to be active the year around. Garden snails are very prolific. They lay as many as 80 eggs, six times a year that's 480 snails per female in one year!

Economic Impact:
Snails and slugs feed on a variety of landscape plants as well as on decaying plant matter. They chew irregular holes the smooth leaves and flowers and do severe damage, particularly to herbaceous and succulent plants. During hot, dry periods or when it is cold, snails seal themselves off with a parchment-like membrane and attach themselves to building walls and windows. This is the time when snails may be the most destructive and costly to building owners and property managers. The slimy secretions that snails use to seal themselves off are very acidic and can cause permanent damage. Pestgon technicians have observed where snail secretions have etched paint, damaged concrete, tile, marble and even glass windows. The circular etchings can often be seen on mirrored glass windows of office buildings, especially those windows at ground level.

Management Methods:
Pestgon believes that the first consideration to the control of garden snails in the commercial landscape is, irrigation practices. The goal should be to reduce or eliminate damp harborage areas. Choice of plant species also plays a role in preventing snails as a serious pest. Pesticidal baits can be used as a regular part of pest control services.