DPI Diary: Giant African Land Snail Population Declining
August 30, 2013
Officials prepare to mark end of Year Two of Eradication Campaign
Since giant African land snails (GALS) were detected in Miami-Dade County neighborhoods in September 2011, teams from the Florida Department of Agriculture and Consumer Services Division of Plant Industry (FDACS/DPI) have collected more than 128,000 of the mollusks. As eradication efforts continue, officials cite a significant decline in the snail population as evidence of the program’s success.
Fortunately, GALS have not been found in any other county in Florida, although extensive surveys continue for the voracious snails that can grow to be eight inches long and attack more than 500 plant species. The giant snail can also damage structures by consuming stucco to obtain calcium to build its shell.
Giant African land snails also pose a threat to public health. Scientists from FDACS/DPI have confirmed some of the captured snails carry the rat lungworm parasite, which can cause a form of meningitis in humans. While no meningitis cases have been traced to the snails in Miami, no one should handle any snail or slug without gloves and everyone should remember to wash hands and fresh produce. A good general rule is to avoid eating raw or undercooked snails, frogs or shrimp/prawns.
All suspected snails should be reported to the Helpline, (1-888-397-1517) and snails should never be moved off-property, handled or consumed. Officials also warn against movement of plant materials from properties where the snail have been found.
The initial GALS find in Miami-Dade County in 2011 resulted in an intensive joint eradication program by FDACS/DPI and the United States Department of Agriculture. Since the detection, the USDA has committed more than $6.5 million in federal funds and the Florida Department of Agriculture and Consumer Services has spent about $1,375,000 on the program.
Currently, FDACS/DPI is managing the program with about 50 employees working in Miami-Dade, conducting survey, control and related program activities. Experts at the FDACS Division of Plant Industry laboratories in Gainesville support the teams in Miami-Dade. Teams of inspectors have found the snails on more than 576 properties in 21 core areas of Miami-Dade.
Public support has been crucial. Officials attribute much of the success of the program to date to residents’ continued vigilance and cooperation with the inspectors. Homeowners continue to call the Helpline when they see suspected giant African land snails and have demonstrated further cooperatoin by allowing inspectors to access their properties for continued survey and control efforts.
A recent development that has contributed to the program’s success was the approval by the U.S. Environmental Protection Agency of the application of a stronger bait on snail-positive and surrounding properties. Snail mortality rates have risen considerably since these applications began, and about 85 percent of recent snail finds have been dead.
The “Look for Them! Report Them!” campaign will continue to spread the word to Miami-Dade residents about the snail, using billboards, bus benches, radio, television and social media, urging residents to watch for the snail and call the Helpline, 1-888-397-1517, if they believe they have seen one.
Giant African Land Snails by the Numbers
Giant African land snails (GALS) were found in Miami-Dade County neighborhoods in September 2011. As eradication efforts continue, officials say a significant decline in the snail population shows the program is succeeding. Extensive surveys continue statewide, but the snail has not been found in any other county in Florida. The snails can grow to be eight inches long and attack more than 500 plant species. The snail can also damage structures by consuming stucco to obtain calcium to build its shell and are known to carry a strain of meningitis to which humans are susceptible. Below are key numbers related to the snail eradication program.
9/8/11: Date the giant African land snail was discovered in Miami
500: Number of agricultural crops known to be consumed by the snail
8” x 4”: Maximum size attained by individuals of the species
Nine: Maximum years in life span of individuals
1,200: Number of eggs an adult can lay in one year
128,000+: Number of GALS found since September 8, 2011
21: Current number of core areas where the snail has been found in Miami-Dade County
576: Number of properties on which snails have been found
2,300+: Number of properties where survey and treatment are routinely conducted
Nine +: Number of years it took to eradicate the snail after it was found in Florida in 1966
17,000: Total number of snails collected in the 1966-1975 eradication program
$1 million: Cost of that eradication (in 1960s dollars)
$7.8 Million: Estimated expenditure since Sept. 8, 2011 on the current eradication effort
One: Number of successful GALS eradication programs on record
1-888-397-1517: Number of the Division of Plant Industry toll-free Helpline
(Numbers as of Aug. 10, 2013)