https://newsday.co.tt/2025/07/20/scourg ... can-snail/Scourge of the giant African snailNewsday 8 Hrs Ago
ALLISON ATTZS
IN Trinidad and Tobago, giant African snails are causing significant problems by damaging crops, posing health risks, and impacting the environment. These pests are nocturnal, moving around at night to feed on a wide range of plants and is considered an invasive species capable of damaging gardens and agricultural land.
They are more active in the rainy season or when conditions are most and may also carry the parasite known as rat lungworm, which can lead to meningitis in humans.
The Giant African snails are not poisonous in the sense of having a venom, but their ability to harbour parasites makes them a health risk.
Where did they come from
The giant African snail originated from East Africa. They were introduced to the Caribbean by people using them as a food source, keeping them as pets, and for certain religious or cultural practices. In Trinidad, the first sighting was in Diego Martin in October 2008, and the snails are now widespread, and have been found in various locations in Trinidad as well as Tobago.
Life cycle
The giant African land snail is a hermaphrodite, meaning each snail possesses both male and female reproductive organs. They mate via cross-fertilisation where both snails’ exchange sperm and can store it for later use after a single mating.
Egg Laying:
They can lay eggs in batches of 200-300 from five to six months of age with a lifespan of three to five years and can potentially live longer up to nine years with hibernation. Each snail can lay up to 1,200 eggs per year.
Egg Incubation and Hatching:
Eggs hatch in about 11 days under ideal condition and newly hatched snails emerge from soil and initially consume their eggshell and other organic matter.
Juvenile and adult stages:
A lettuce nursery is left in ruins after being attacked by giant African snails. - Photos courtesy Elizabeth Chin
Juveniles remain underground for a period of five-15 days before emerging to feed on plants and debris and they establish a home range within two months. Adult snails are primarily nocturnal and sensitive to evaporation, often hiding during the day in cooler, moist environments.
Importance of snails to ecosystem
Giant African snails are not beneficial to ecosystems. They are an invasive species that can cause significant damage to both the environment and agriculture. Their voracious appetite for plants disrupts natural habitats and can decimate crops. Additionally, they can be a vector for human diseases, making them a public health concern.
How they move around
Giant African snails spread to new locations primarily through accidental transport via vehicles, movement of materials, and waterways
Vehicles:
Giant African snails can hitch rides on vehicles by clinging to the undercarriage.
Movement of materials:
Infested soil, garbage, and plant debris can also spread the snails.
Waterways:
Rivers and floods can carry snails and their eggs downstream.
Activity:
They can travel up to 50 metres in a single night, moving on their slime trail.
Community effort
Community participation is crucial for effectively managing and eradicating the Giant African snail’s population. Individuals can help by collecting snails, using baiting methods, and removing potential snail habitats and participating in community clean-up efforts are also vital.
Manual Removal:
Collect snails, especially at night when they are most active, and dispose of them properly (eg submerging in salt or bleach solution for 24 hours, then dispose of the remains in a garbage bag, burn them in a safe contained area, or bury them at least two feet deep.
Baiting:
Utilising snail and slug bait which contains metaldehyde is the most effective but its toxic to pets. Safer brands that contain Iron Phosphate can be used around pets and can be spread around the home, field or vacant lots. They can be purchased from most agricultural shops around TT.
Habitat Modification:
Remove potential hiding places like mulch, wood pile, and dense vegetation, as snails thrive in humid environments.
Sanitation:
Sanitise fruits and vegetables with a vinegar or bleach solution before consumption as this helps minimise the risk of pathogens that are harmful to humans.
Natural Predators:
Several bird species are known to prey on Giant African snails, including guinea fowl, some species of ibis, and certain types of thrushes. In Trinidad, the painted wood turtle and opossum have also been observed consuming these snails.
Routine scouting:
Regularly inspect areas for signs of snails, especially after baiting or spraying, to ensure eradication efforts are effective.
Remember, this land snail is one of the most damaging snails in the world and consumes at least 500 different types of plants. They ca be devastating to agriculture and natural areas as they cause extensive damage to tropical and subtropical environments. This is a community collaboration, and we must come together to assist in eradicating the Giant African snail.
For further information contact the Eastern Horticultural Club at 263-3866, or
easternhorticultural@hotmail.com The Club meet on a Saturday of every month (except public holidays) at 3 pm at the YWCA, Gordon Street, St Augustine.
