Giant African Snails
Written October 2011
This September, Giant African land snails were detected in Miami-Dade County.
These invasive snails are considered to be one of the most damaging species of land snails--they feed on over 500 kinds of plants and are a serious threat to Florida's agriculture, natural areas, and landscapes.
They can also cause damage to plaster and stucco structures and may carry a parasitic nematode that causes meningitis in humans.
Keep an eye out for these invasive snails, which can grow up to 8 inches in length and more than 4 inches wide. Giant African snails feed on plants at night. They hide among plants or under debris or soil during the day.
Look for signs of feeding, or search for them out in the open at night; on cloudy, rainy days; or on sunny days in damp, shady areas.
Giant African land snails often are large enough to be seen easily, so they can be collected by hand. It is advised to wear gloves, however, or to use an implement to pick up the snails because they can pose a serious health risk to humans. If you do collect snails, seal them in a plastic bag and then place the bag in a bucket or plastic container.
Contact FDACS at 888-397-1517 and a specialist will come to collect and properly dispose of them.
Snails Favor High Humidity
To discourage these land snails in your yard, eliminate mulches, ground cover, and other dense vegetation that would provide them a moist, sheltering environment. This does go against our Florida-Friendly recommendations for landscaping; however, your local county Extension agent should be able to give you other Florida-Friendly options to help keep a snail-free yard.
Reduce the amount of irrigation to deny snails the moist environment they prefer.
Snails Are Susceptible to Traps
A board, flower-pot saucer, or unglazed flower pot placed in a shady location can serve as a suitable refuge for snails, where they can then be hand-collected and destroyed.
The Giant African land snail seems to be particularly attracted to banana and papaya fruit, so these can be used as baits to attract them.
Kill Snails with Slug and Snail Baits
Newer mollusc baits contain iron phosphate as a toxicant. Iron phosphate is normally thought of as a fertilizer, but will also control snails and is the most environmentally-friendly product currently available. Iron phosphate baits are used in a variety of settings, such as lawns, gardens and non-crop areas.
Snail baits that contain toxicants are available at garden centers, but should be used in accordance with label instructions. Scatter the bait material among susceptible plants, as this will increase the probability that snails will find and eat the lethal bait.
Metaldehyde-containing baits have long been useful, and remain available. Although effective, metaldehyde-containing formulations are quite toxic to pets and wildlife, so we discourage their use.
Bait formulations containing boric acid also are available. Though not yet thoroughly proven, boric acid-containing baits seem promising for Giant African snail control.
For more information on Giant African snails, contact Dr. John Capinera.
Related Sites & Articles
- UF/IFAS Publications
- First Detector News (4.44MB pdf)
- Giant African Land Snail in Florida
- Other Sites & Publications
- Giant African Land Snail--Florida Department of Agriculture & Consumer Services