Update on the Giant African Snail (GAS) in Miami-Dade County, FL 18th Annual Southwest Florida Invasive Species Workshop Eduardo M. Varona USDA APHIS PPQ State Operations Support Officer January 23, 2014
Update on the Giant African Snail (GAS) in Miami-Dade
County, FL
18th Annual Southwest Florida Invasive Species
Workshop
Eduardo M. Varona
USDA APHIS PPQ
State Operations Support Officer
January 23, 2014
History (Global)
• 1800’s started the migration from East Africa
• Mid 1930’s Hawaii - established
• Late 1940’s first detections in United States - contained
• 1958 Arizona - contained
• 1966 North Miami – 10 year successful eradication
• 2004 U.S. pets stores and schools –contained
• 2011 Miami-Dade County – ongoing eradication
• Current world distribution in the Americas includes: some Caribbean islands, and countries such as Colombia, Brazil, Ecuador, and others.
Pathways into the US
• Internet/mail
• Ceremonial use
• Pets
• Cosmetics
• Cargo
• Smuggling
• Hitchhiking
• General and permit cargo – 35
• Passenger baggage and miscellaneous – 34
• Mail - 8
• Total entries -77
USDA database query entries for Achatinadea
(01/2003 to present)
Biology
Lissachatina fulica Bowdich
Biology
• GAS is a major plant pest that consumes more than 500 varieties of plants.
• GAS can harbor the rat lungworm nematode, which can cause a rare form of meningitis in humans and animals.
Biology
• GAS can grow up to 8 inches in length.
• Adult GAS typically lay up to 1,200 eggs annually…
• There is no known natural predator in Florida for GAS
• GAS are hermaphroditic
Biology
• In lab tests, self-fertilization by GAS was possible when optimal mating conditions were not present. F1 viable.
• In lab tests, paired GAS can produce up to 730 eggs/month with a 51% viability
• Largest # of eggs produced in one clutch, 1,082
• In lab tests, specimens (neonates) can survive up to 97 days without food.
Current Eradication Program Overview
• First find on September 9, 2011- resident report to FDACS
• Field efforts carried out primarily by FDACS employees (51)
with significant USDA funding through a cooperative
agreement ($6.5 million to present)
• 25 Cores identified positive in Miami-Dade County, Florida w/
636 positive properties
• Since the inception of the Program to date:
– 89,177 inspections
– 50,131 treatments
– 137,809 GAS specimens collected.
Survey Process
• Twice monthly site visit
• Remove small yard debris
• Manual collection snails
– # per property
– % mortality
– Age structure
• Egg mass
– # eggs
– % viable embryos
• Shell length
• Treat site with Metaldehyde
Other Trends
• Mean size of collected shell has decreased
• Possible sublethal effects due to
treatments
– Fecundity
– Egg viability
• New cores detected after October 2011
and presently are much smaller in area,
lower in number of positive properties, and
contain smaller snail populations
– Cores 1-12 - average ~ 46 positive properties/core
– Cores 12-25 - average ~ 5 positive properties/core Julio Rodriguez, FDACS 2011
• Better traps – preventing escape
• Better baits – durable, clean, low cost
• New treatment formulations
• Aggregation pheromones
• Detector dogs – snails in hiding
Detector dogs in training…
will be used to assist in finding GAS
where human limitations exist, providing an a
an additional tool in the eradication effort.
Other Tools
Rat Lungworm
• Confirmed in GAS
October 2012
• 7 positive core areas
– Further research to
explore distribution
within cores
– Increased sampling in
other cores
Lindo et al. 2002
• GAS are known
carriers of
Angiostrongylus
Cantonenss (Rat
Lung Worm), which
can produce a rare
form of eosinophilic
meningitis, for which
there is no known
cure.
Outreach
Has been vital in identifying new infested areas in Miami-Dade
County and garnering ongoing support for program control activities.
Efforts have included: press events, radio/tv spots, national and
international coverage, bus benches, billboards, newspaper adds,
movie theatre advertising, school events, pet amnesty day booths,
natural areas managers workshops, and many others…
Of 25 infested “core’’ areas a full 90% of them have been detected as
a result of residents calling in with leads of “I think I have GAS on my
property”
Impacts to:
Human Health
• Rat Lung Worm -
meningitis
• Organic growers
• Home gardens
Natural Environment
Agriculture
• 500 Crops
• High reproduction rate -
increased management costs
• Economic damage - trade
• Public nuisance in urban areas
Outreach messages…
• Home grown potted plants and yard equipment
• Ceremonial practices
• Illegal dumping of debris (organic and inorganic)
• Collectors/purposeful introduction
• A pet snail
• Vehicles
• Internet
• Cargo
Potential modes of movement into SW FL
What We Are
Doing
Using Metaldehyde-
based products
Mechanical Collection
Inspecting Landfills and
Transfer Stations
Regulating
Landscapers, Lawn
Maintenance and
Botanicas
Public Outreach
How You Can Help
• Don’t move home grown potted plant material and yard equipment from or near infested areas to SW FL
• Monitor areas in your community with strong connections to infested areas
• Monitor illegal dumpsites particularly if materials there are suspected from SE FL
• Spread the word in your community
• Call if you suspect you have GAS
FDACS-GALS Hotline
1-888-397-1517
Bill Torres, GALS Program
Director (FDACS)
Office: (305) 278-0340 [email protected]
Eduardo M. Varona
USDA APHIS PPQ
State Operations Support Officer
(305)278-4873 Office
(305) 986-4407 Cell
To learn more about GAS and other pests of
concern to USDA, our state, and your community
go to USDA’s….
http://www.hungrypests.com/
Circle of Life?
Questions?