Giant African snail invasion lands part of Florida in quarantine

TAMPA, Fla. (WFLA/NEXSTAR) — Part of Southwest Florida was placed under quarantine in an effort to stop the spread of one of the most damaging snails in the world.

The giant African snail, or “GAS” for short, (it can also be called giant African land snail, or “GALS”) can consume at least 500 different types of plants and be devastating to Florida’s agriculture, according to the state Department of Agriculture and Consumer Services.

Not only does this slimy species possess a mighty appetite, “the snails also pose a serious health risk to humans by carrying the parasite rat lungworm, known to cause meningitis in humans,” the department wrote in an online quarantine advisory.

However, the latest quarantine efforts in Florida’s Lee and Pasco counties are not the state’s first attempts at eradicating the species.

The giant African snail has been eradicated from Florida twice already. The snail was first detected in 1969 and was eradicated in 1975. In 2011, the snail was again detected in Miami-Dade County and eventually eradicated in 2021.

Finally, on June 23, 2022, the Florida Department of Agriculture and Consumer Services (FDACS) confirmed the detection of the giant African land snail in the New Port Richey area of Pasco County.

That same month, FDACS’s Division of Plant Industry began to survey the area and enacted a quarantine.

Officials said the populations previously eradicated in South Florida and the population in Lee County have dark brown shells with grayish-brown flesh. The snails detected in Pasco County have light to dark brown shells with milky white flesh (seen below).

(Department of Agriculture and Consumer Services)

To protect your property, FDACS reccommends Metaldehyde, a pesticide used to control snails and slugs. The treatment option is approved for use in a variety of vegetable and ornamental crops in the field or greenhouse, on fruit trees, small-fruit plants, in avocado and citrus orchards, berry plants, banana plants and in limited residential areas.

Property owners inside the treatment area will be notified in person or by posted notice at least 24 hours in advance of the planned pesticide treatment. For more information, click here.

Why is it so hard to stop them?

GAS populations are difficult to suppress for a few reasons, the U.S. Department of Agriculture explains. The snails have both male and female reproductive organs — and each snail can produce up to 1,200 eggs each year. Additionally, snails can reproduce several times from a single mating. Research also shows that GAS eggs are hardy, with a 90% survival rate.

Research published in the peer-reviewed PLOS One journal showed that 100 GAS hatchlings were potentially capable of producing over 1,000 more within 270 days.

The snails are so detrimental to ecosystems, they’re considered prohibited organisms in the U.S. Last week, U.S. Customs and Border Protection said specialists intercepted six GAS at Detroit Metropolitan Airport inside the suitcase of a traveler from Ghana. Penalties for traveling with the species — which are eaten and even kept as pets overseas — can include penalties and arrest, CBP says.