Giant African Land Snail

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Giant African Land Snail
In Florida
Paul Skelley, FDACS-DPI
Identification
Full grown, this snail
can reach up to 20 cm
in length and 12 cm in
diameter. Its shell is
usually dark and light
brown and swirls wrap
around its cone like
shell.
Giant African Land Snail (GALS)
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Native to East Africa
Has become a world wide pest in tropical
countries, including southeastern Caribbean
countries and several countries in South America.
In other countries, it is a popular pet and used for
educational purposes. It is also used in some
religious rituals.
Introductions can be intentional or accidental.
Pest Status: Host Plants
The Giant African Land Snail,
Achatina (Lissachatina)
fulica, is considered one of
the most damaging snails in
the world. It is known to feed
on at least 500 different types
of plants.
Image: http://www.fao.org/forestry/30381/en/
Other Hosts
In addition to fruits
and plants, GALS will
forage on animal
matter, lichens, algae,
and fungi.
They have even been
known to feed on
stucco.
Photo: FDACS/DPI
Rapid Reproduction
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The Giant African Land
Snail begins laying eggs
at 5-6 months old. A
single snail can produce
from 300 to 1000 eggs in
3-4 batches per year.
The eggs usually hatch 820 days after mating.
Their lifespan lasts about
3-5 years.
Photo Credit: David Robinson, USDA-APHIS-PPQ
Medical Importance
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Public Health Concerns:
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Intermediate vector for:
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rat lungworm,
Angiostrongylus cantonensis
(roundworm) which causes
eosinophilic meningitis in
humans
Aeromonas hydrophila
(bacteria)
Diseases (?) through their
slime
Establishment and
Eradication in Florida
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In 1966, a Miami boy
smuggled three Giant African
Land Snails into Florida from
his vacation. His
grandmother released them
into her garden, and in seven
years, there were more than
18,000 of them. The Florida
state eradication effort took
years of work but GAS was
eradicated in the early 1970s.
Photo Credit: West Virginia Department of Agriculture
http://www.wvagriculture.org/news_releases/2004/5-17-04.htm
New Establishment
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Discovery Sept. 8, 2011
in a Coral Gables
neighborhood, initiated
intense survey by
USDA, FDACS-DPI,
and CAPS
As of Sept 13, GALS
was found at over 30
residences in the
neighborhood, one
residence having over
200 snails collected.
Photo Credit: West Virginia Department of Agriculture
http://www.wvagriculture.org/news_releases/2004/5-17-04.htm
Present Efforts
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Survey work continues to
delimit the population and look
for others, as GALS are easily
transported by human activities.
Educational outreach is planned
to gain more information.
Eradication measures are being
discussed, as allowing GAS to
become fully established is not
an option.
Early in the Game
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Unlike eradicating the
Mediterranean fruit fly,
where we’ve had lots of
practice. Eradication of
this snail has many facets
to consider and resolve
in our present society.
But we must act fast or
live with the
consequences.
GALS compared with some native Florida tree
snails.
Photo credit: FDACS/DPI
GALS Potential Distribution
in the USA
Movement on commodity
Survival in transit
Ability to colonize
Ability to spread
= probability of establishment
Based on parameters:
Zhou et. al. 1998
Raut & Barker 2002
Special Thanks
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Southern Plant Diagnostic Network (SPDN)
Stephanie Stocks and Amanda Hodges, UFIFAS/SPDN
Trevor Smith, FDACS/DPI
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