Invasive Snails
This page focuses on three important invasive snails: Giant African Land Snail (Lissachatina fulica), Golden Apple Snails (Pomacea canaliculata and P. maculata), and the Peanut Snail (Bulimulus sporadicus).
Figure. 1. Invasive snails ( Bulimulus sporadicus) on corn leaves.
Photo by: University of Florida
Introduction
Invasive snails cause serious threats to agriculture, ecosystems, and biodiversity. They spread rapidly through soil, water, and global trade, damaging crops and disrupting natural habitats. Among the most destructive are the Giant African Land Snail (Lissachatina fulica), Golden Apple Snails (Pomacea canaliculata and P. maculata), and the Peanut Snail (Bulimulus sporadicus). These species feed on rice, vegetables, and fruit crops, and can clog irrigation systems, affecting water flow and agricultural productivity.
Giant African Land Snail (Lissachatina fulica)
The Giant African Snail (Achatina fulica Férussac, 1821; family Achatinidae) is a highly invasive land snail native to East Africa. Recognized by the Global Invasive Species Database as one of the world’s most damaging invasive species, it ranks second among all alien species globally. It has spread to many regions globally, particularly impacting tropical and subtropical areas.(Sarma et al., 2015).
What to look for
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Can grow up to six times the size of an ordinary garden snail
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Feature a distinct conical shell that’s typically twice as long as it is wide
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Possess an elongated, cone-shaped shell measuring about 5–10 cm in length, sometimes reaching up to 20 cm
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Shell color varies, though it is commonly light brown with alternating brown and cream bands on the upper whorls
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Produce oval-shaped, cream to yellow eggs about 5 mm in diameter, usually laid in clusters of 100–400
Figure 2. Giant African snail
Photo credit: Pest and Diseases Image Library, Bugwood.org
Think you found a giant African land snail? Refer to the ID sheet
Where to Find Them
They are most active during humid or rainy conditions, particularly after sunset. At night, they feed on fruits, vegetables, and even pet food left outdoors. During the day, they often rest on walls near air conditioners or water sources, or bury themselves in loose topsoil. Egg-laying typically occurs in moist areas rich in decaying organic matter, within the top few inches of soil. Juvenile snails may remain underground for two to six months before emerging to the surface. (CISMA, 2025).
Current distribution
The Giant African Snail has established populations across much of tropical Asia, Africa (beyond its native range), the Indo-Pacific, and parts of the Americas. It is now widespread throughout Southeast Asia and South Asia, including countries such as India, southern China, Thailand, Malaysia, Indonesia, the Philippines, and Vietnam, as well as numerous islands across the Indian and Pacific Oceans. The species has also invaded both East and West African regions outside its native range, and parts of the Neotropics, extending from the Caribbean and northern South America to isolated areas in Central America. (CABI, 2013).
Figure 3. African giant snail distribution
Source: EPPO Global Database
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Risks and Damage
African giant snail is classified among the world’s worst invasive species due to the wide-ranging damage it can cause (CABI, 2022). A. fulica has an extremely wide-ranging diet. It prefers decayed vegetation and animal matter, lichens, algae and fungi. However, it has been recorded on a large number of plants including most ornamentals, and vegetables (CABI, 2022). Infestations of these snails cause both direct and indirect impacts on agriculture, human and animal health, as well as urban environments and infrastructure.
Agricultural destruction: Giant African snails are major crop pests as they feed on an enormous variety of plants everything from vegetables and fruits to ornamentals and tree bark. Entire rows of seedlings or vegetable plots can be wiped out virtually overnight by masses of these snails, leaving only slime trails and foul-smelling excrement behind (CISMA, 2025)
Human and animal health: L. fulica causes a public health concern because it is a known vector of parasites that can infect humans and other animals. This snail is a carrier of the rat lungworm (Angiostrongylus cantonensis), a nematode that causes eosinophilic meningitis in humans (USDA, 2022)
Urban and infrastructure damage: Unlikely as it sounds, giant African snails can also cause damage to infrastructure and causes safety hazards. As noted, they have a habit of consuming calcium-rich substances – meaning they will chew on plaster, drywall, stucco, and even paint on buildings to obtain calcium for their shells (CISMA, 2025; Live science, 2013)
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Management, Control & Prevention
Quarantine & Prevention: The most effective way to control these snails is to prevent their introduction. This involves restricting the import or movement of snails, soil, and plants from infested regions. Early detection and rapid response are essential to stop their establishment and spread (USDA, 2018; FDACS, 2025).
Physical control: In areas where these snails are already established, a fundamental control approach involves manually collecting and destroying both snails and their eggs. Community groups or volunteer teams can be mobilized to hand-pick snails, typically at night or in the early morning when they are most active, and to locate and remove egg clusters from the soil. This method proved effective during Florida’s eradication program (2011–2021) (GISD, 2010).
Chemical control: Molluscicides (slug/snail pesticides) are a common tool in battling L. fulica, especially when infestations cover large areas or dense foliage where hand-picking is impractical. Traditional chemicals like metaldehydeand calcium arsenate have long been used to kill snails (GISD, 2010)
Video
Source: CNN Youtube (Why giant snails are a problem for Florida
Golden Apple Snails: Pomacea canaliculata and Pomacea maculata
Golden Apple Snails are large freshwater snails belonging to the apple snail family (Ampullariidae). Two closely related species – Pomacea canaliculata (the channeled apple snail) and Pomacea maculata (the giant apple snail) – are often collectively referred to as “golden apple snail". Both species are native to South America but have been widely introduced to other parts of the world, including East and Southeast Asia, several islands in the Pacific, the southeastern United States, and even parts of Europe (Yang et al., 2018)
In fact, P. canaliculata is listed among “100 of the world’s worst invasive alien species” due to its extensive impacts (Buddie et al., 2021)
What it does
Golden apple snails feed on young and emerging rice plants, cutting the stems at the base and completely destroying the seedlings. This damage can severely reduce rice yields, especially during the early growth stages.(Rusli et al., 2023 ; CABI, 2021)
How to identify
To differentiate golden apple snails from native species, observe their color and size. These snails typically have a muddy-brown shell with golden-pink or orange-yellow flesh. They are generally larger and paler than native snails, and their egg clusters are bright pink, often found above the water’s surface (IRRI, 2025)
Figure 4. Eggs mass
Photo credit: CABI
Figure 5. Golden Apple Snail (GAS)
Photo credit: IRRI
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Why are they consider as important pest?
Ecological and Economic Impact
Golden apple snails are highly destructive herbivores in aquatic environments, causing serious damage to agricultural systems. Crops like rice and taro that grow in flooded conditions are especially vulnerable to infestation (CABI, 2022). As a major rice-producing region, Southeast Asia is especially at risk. In the Philippines, for example, an estimated 1.2–1.6 million hectares of rice fields were already affected by these snails in the early 1990s (YUMPU, 2013).
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Management and Control Strategies
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Mechanical/Physical Control: Hand-picking and trapping are simple but important measures, especially in small paddies or waterways.
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Egg cluster removal is also effective: regularly scraping those pink egg masses off vegetation or walls and destroying them prevents thousands of hatchlings.
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Chemical Control: Molluscicide pesticides are used in many places, but with caution due to cost and environmental side effects. Two common chemical molluscicides are niclosamide and metaldehyde.
Community-based snail management:
To best control the snail, communities should work together to reduce snail numbers in their area.
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Organize community-wide campaigns to collect snails and their eggs during land preparation, planting, or early crop establishment stages
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Keep fields as dry as possible during the early growth stages of rice (under 30 days old), or alternatively, transplant 25–30-day-old seedlings from low-density nursery beds to minimize damage from snails
More Information
Life Cycle of Apple snails? Watch this
Source: CABI PlantWise
Peanut Snail (Bulimulus sporadicus)
Bulimulus sporadicus is a small terrestrial snail originally native to Central and South America and the Caribbean. It has no true established common name in its native range, but in invaded areas it’s often called the peanut snail or ghost snail due to its shape and sudden mass appearances. This species was first detected outside its native range in Florida (USA) in 2009, and it has since spread into many new areas (Citrus Industry, 2024)
Identification
Bulimulus sporadicus, has a slender conical shell (up to ~30 mm long) that darkens toward the tip (Citrus Australia, 2025). This invasive land snail is tan-colored and often congregates in unusually large numbers, especially in humid areas around irrigation lines.
Key features include:
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A slim, conical shell which darkens slightly toward the top; the body is tan-colored
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Usually under 30 millimeters long, and often much smaller
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Small, shiny white spherical eggs buried just below the soil surface
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Gathering in unusually large numbers, especially around irrigation lines
Figure 6. Adult of Bulimulus sporadicus
Photo credit: Spineback, Dreamstime.com
Look-alikes
Bulimulus sporadicus may share some features with other important snails, such as the Amber snail and the Giant African Land Snail. Check here to learn how to distinguish them.
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Importance of the Pest and Damage Caused
Crop damage:
The peanut snail is considered an important agricultural pest because it can attack a wide range of plants. This snail has been reported feeding on citrus, cotton, soybean, blueberry, peanut, and other crops. The impact is often indirect such as large aggregations clog drip irrigation and microsprinkler heads, disrupting water supply in crops like citrus (Citrus Australia, 2025). They also feed on plant tissues that are already damaged (e.g. frost-injured bark or fruit), sometimes girdling young trees and exacerbating crop stress (Citrus Australia, 2025; Citrus Industry, 2024)
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Management strategies
Figure 7. Adult of Bulimulus sporadicus invaded a tree
Photo credit: University of Florida
WHAT WORKS
Snails favor high humidity and take shelter in places such as vegetation, mulch or leaf litter that provide them with a moist environment. Keeping the ground under the tree canopy free of weeds will help reduce their habitat.
Tree wraps may also provide shelter for snails. Removing tree wraps as soon as practical may also help reduce numbers.
Snails can be managed chemically with molluscicides. Molluscicides target slugs and snails. Specially formulated molluscicide baits are available and labeled for use in citrus.
Chemistries that have been tested and have proven to be efficient for peanut snails include metaldehyde, 4% (Deadline), iron phosphate + spinosad (Bug-N-Sluggo) and sodium ferric EDTA (Ferroxx)
Several traps have been developed to capture snails in large quantities. One of these, known as Snailer, can be particularly effective when supplemented with a lure made of fermented bread dough
Status in Southeast Asia
As of 2025, Peanut snails have not been widely reported as established in Southeast Asia – and regional authorities aim to keep it that way. Most countries in the region are on alert due to the snail’s spread elsewhere. The region’s extensive trade connections mean constant vigilance is needed. As the country neighbour such as Australia had a scare in 2023–2025 when peanut snails were detected at the Port of Brisbane, a major shipping port. Over 350 snails were found, and eradication measures were launched quickly to prevent establishment. This incident underlined how easily the snail can slip into new
More information
To learn more, watch this lecture on Bulimulus sporadicus from the University of Florida.