IDENTIFICATION AND BIOLOGY 
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 signals the presence of these pests. Adult brown garden snails lay about 80 spherical, pearly white eggs at a time into a hole in the topsoil. They may lay eggs up to six times a year. It takes about 2 years for snails to mature. Slugs reach maturity in about a year. 

Snails and slugs are most active at night and on cloudy or foggy days. On sunny days they seek hiding places out of the heat and sun; often the only clues to their presence are their silvery trails and plant damage. In mild-winter areas such as in southern California and in coastal locations, young snails and slugs are active throughout the year. 

During cold weather, snails and slugs hibernate in the topsoil. During hot, dry periods, snails seal themselves off with a parchmentlike membrane and often attach themselves to tree trunks, fences, or walls. 

DAMAGE
Snails and slugs feed on a variety of living plants as well as on decaying plant matter. On plants they chew irregular holes with smooth edges in leaves and can clip succulent plant parts. They can also chew fruit and young plant bark. Because they prefer succulent foliage, they are primarily pests of seedlings, herbaceous plants, and ripening fruits [69K],such as strawberries, artichokes, and tomatoes, that are close to the ground. However, they will also feed on foliage and fruit of some trees; citrus are especially susceptible to damage. 

MANAGEMENT 
A good snail and slug management program relies on a combination of methods. The first step is to eliminate, to the extent possible, all places where snails or slugs can hide during the day. Boards, stones, debris, weedy areas around tree trunks, leafy branches growing close to the ground, and dense ground covers such as ivy are ideal sheltering spots. There will be shelters that are not possible to eliminate-- e.g., low ledges on fences, the undersides of wooden decks, and water meter boxes. Make a regular practice of removing snails and slugs in these areas. Also, locate vegetable gardens or susceptible plants as far away as possible from these areas. Reducing hiding places allows fewer snails and slugs to survive. The survivors congregate in the remaining shelters, where they can more easily be located and controlled. Also, switching from sprinkler irrigation to drip irrigation will reduce humidity and moist surfaces, making the habitat less favorable for these pests. 

Handpicking
Handpicking can be very effective if done thoroughly on a regular basis. At first it should be done daily; after the population has noticeably declined, a weekly handpicking may be sufficient. To draw out snails, water the infested area in the late afternoon. After dark, search them out using a flashlight, pick them up (rubber gloves are handy when slugs are involved), place them in a plastic bag, and dispose of them in the trash; or they can be put in a bucket with soapy water and then disposed of in your compost pile. Alternatively, captured snails and slugs can be crushed and left in the garden. 

Traps 
Snails and slugs can be trapped under boards or flower pots positioned throughout the garden and landscape. You can make traps from 12" x 15" boards (or any easy-to-handle size) raised off the ground by 1-inch runners. The runners make it easy for the pests to crawl underneath. Scrape off the accumulated snails and slugs daily and destroy them. Crushing is the most common method of destruction. Do not use salt to destroy snails and slugs; it will increase soil salinity. Beer-baited traps have been used to trap and drown slugs and snails; however, they attract slugs and snails within an area of only a few feet, and must be refilled every few days to keep the level deep enough to drown the mollusks. If using beer, it is more effective fresh than flat. Traps must have vertical sides to keep the snails and slugs from crawling out. Snail and slug traps can also be purchased at garden supply stores. This article copyright © 1995-2001 by the Regents of the University of California. All rights reserved.