MIAMI – The giant African land snail, which can reach the size of a fist and carry a parasite that causes meningitis, was declared eradicated from South Florida last year after a decade of battle against pests.
They are baaack.
The dreaded snails, known to connoisseurs of invasive species as GALS, were spotted in June by a gardener in Pasco County, north of Tampa, the first time a population outside South Florida has been detected.
To try to contain them, state officials put a portion of Pasco County in the New Port Richey area in quarantine this week. Plants, garden waste, debris, compost or building materials cannot be legally moved without permission, for fear of sticky molluscs spreading. Quarantine extends from a radius of about half a mile from the identified snail population and may change or grow if more snails are found.
The return of the snails was a startling and unwanted development in a state where wildlife usually appears in the headlines: a 215-pound Burmese python was caught late last year in the Everglades, and where invasive species often cause havoc. During a particularly rainy spring a few years ago, Palm Beach County exterminators received a wave of calls about Bufo toads, whose toxin is so poisonous that it can kill dogs, which are found paired in swimming pools.
“Pasco County is a little drier than South Florida because you have this large area of scrub habitat,” said Bill Kern, an associate professor at the University of Florida who specializes in annoying wildlife management. African ground giant snails usually “like moisture and like dense vegetation.”
“Of course, in areas that are irrigated, such as nurseries or home landscapes, they will be perfectly happy,” he added.
African giant snails are “one of the most invasive pests on the planet,” according to the Florida Department of Agriculture and Consumer Services. They eat more than 500 types of plants, and also feed on stucco, “as a source of calcium.” They hide in cool, humid places during the day, feed at night and lay many thousands of eggs throughout their lives. Some snails can grow up to eight inches long and five inches wide.
They can also carry a parasite, the rat lung worm, which causes meningitis in humans and animals, if, for example, people eat unwashed lettuce or other products that the carrier snail has slipped, leaving behind a trail of slime.
“DON’T DRIVE SCREWS WITHOUT WEARING GLOVES!” warned the agriculture department.
Dealing with invasive species that are destructive and not just a nuisance can be very costly, Drs. Kern. Floridans spend about $ 100 million a year to fight a single plague: the West Indies dry wood termite.
On Wednesday, the state began treating Pasco County’s quarantine area with a snail bait containing metaldehyde, a pesticide approved for use in vegetable and ornamental crops, fruit trees and other plants that disrupts the digestive system. of the African giant snails and kills them. .
Mellon, a rescue labrador specifically trained to spot giant African land snails, has been “actively exploring” the area, according to the agriculture department, which owns several dogs that sniff out pests. (They sit when they smell a snail.)
Florida has already eradicated the snails twice before: last year, after appearing in Miami-Dade County in 2011, and in 1975, after its initial detection in the state in 1969. agriculture announced in 2021 that a giant African land snail had not been found in Miami-Dade County since 2017, following an eradication effort in which more than 168,000 snails were collected.
The snails identified in Pasco County look different from those previously seen in Miami-Dade County: their flesh is creamy white, rather than greyish brown.
The color makes state officials suspect that the snail population in Pasco County could have started from a pet snail released into the wild. Creamy white meat “is the most desirable trait for the illegal pet trade,” said Christina Chitty, director of public information for the plant industry’s plant industry division. Giant African land snails are illegal to import into the United States without permission.
Still, this is just an intuition. “We probably won’t know what the population of Pasco County was like,” Dr. Kern said.