Slugs and Snails

Injury: 

Slugs and snails are often present in greenhouses throughout the year and in home vegetable gardens, flower and ornamental borders during most of the summer. Injury to plants consists of chewed holes in leaves (Figure 4.), stems, flowers and fruit. Seedlings may be totally destroyed.

Description:

Slugs and snails are mollusks, a group of invertebrate animals with soft non-segmented bodies. Slugs are often described as snails without a shell (Figure 1.), while snails' bodies are enclosed in calcareous shells (Figure 2.). Slugs and snails move along by secreting a path of mucus.

Life History:

Many species overwinter in the egg stage, but eggs may also be found at other times of the year. The eggs resemble little round spheres (Figure 3.), are whitish to clear in color, and are often found in masses just below the soil surface. The young slugs resemble the adults and begin feeding as soon as they hatch. The life span for most species is usually less than one year.

Immature and adult slugs and snails that overwinter become active in the early spring when temperatures are consistently above 40^oF (5^oC). A wet spring and early summer usually result in a buildup of slug populations. Dry weather is often detrimental to slugs, and they may either die or burrow deeper into the soil to await moist conditions. Cool damp fall weather is conducive to much slug injury.

Slugs and snails are active mostly at night, and the slime trail they leave is an indication of their presence. Early in the morning this trail may appear as silver streaks on the plant surface, but as the day progresses it dries out and becomes less visible. (In contrast, caterpillars, which cause similar feeding injury, do not leave a slime trail.)

Management:

Slugs and snails need a certain amount of humidity and moisture to survive. In home gardens, staking or caging plants (such as tomatoes to get the fruit up off the ground) allows air to circulate and dry the ground around the plant, and allows foliage to dry, thus making them less likely to be attacked by slugs. Hand picking provides limited control and is tedious, but avoids the use of chemicals. Overturned grapefruit skins and old boards are sometimes used as traps. Slugs will tend to accumulate under or in such articles during the hottest, driest part of the day. Hand pick and destroy slugs or snails as found.

Control of slugs and snails outside of the home:

If needed, use diatomaceous earth (a safe, non-chemical alternative), metaldehyde bait*,  carbaryl bait*, or 1% iron phosphate as per label directions.

 Bonide Slug Magic, Bayer Advanced Natria Slug & Snail Killer, and Sluggo are all natural slug and snail killers that are safe to use around pets and wildlife.

* Caution: some baits may resemble pet food. Be sure to use according to the label directions and place where pets or children cannot get into them.

 

Control of slugs and snails in vegetables:

If needed use diatomaceous earth (a safe, non-chemical alternative), metaldehyde bait, carbaryl bait,  or 1% iron phosphate.

Bonide Slug Magic, Bayer Advanced Natria Slug & Snail Killer, and Sluggo are all natural slug and snail killers that are safe to use around pets and wildlife.

Apply to the ground surrounding plants according to the label directions.

5/95 Prepared by: Carolyn Klass, Senior Extension Associate, Cornell University

Pesticide recommendations obtained from: Part II -- Pest Management Around the Home, 2005-2006 Pesticide Guidelines, Miscellaneous Bulletin 139S74II, A Cornell Cooperative Extension Publication.

This publication contains pesticide recommendations. Changes in pesticide regulations occur constantly and human errors are still possible. Some materials mentioned may no longer be available, and some uses may no longer be legal.

Recommendations and pesticide use may vary depending on on which state you live in.

Read the label before applying any pesticide.

TK: 5/2006

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