A closer look at snail varieties and control measures
WE are often faced with many destructive pests in our gardens. There are several varieties of snails locally from tiny to big ones such as giant African snails (Lissachatina fulica), which belong to the family Achatinidae. Bait can stop them in their tracks but there are other effective alternatives too. African snail These snails from eastern Africa have reached many parts of the world either on purpose or by accident. This snail is capable of aestivating itself for up to three years during extreme drought by sealing itself into its shell with the secretion of a calcareous compound.
It was actually introduced to Malaysia when early duck farmers were looking for a readily available feed. They brought the snail back from Singapore in the 1900s. Once here, the snails were quickly distributed along the length and breadth of Malaysia.
During the Japanese occupation from 1942 to 1945, the African snail was actually known locally as Japanese snails. It became a great pest to vegetable farmers during this period, leading the Japanese authorities to conduct an eradication campaign. It was a horrendous exercise as it was quite impossible to totally eliminate the eggs.
This snail eats a wide range of plant material, fruits, and vegetables. It also consumes sand or calcium for healthy shell growth. The snail is a hermaphrodite, meaning it has both testes and ovaries, and is capable of producing both sperm and eggs, thus self-fertilisation is possible but rare because cross fertilisation is common. Interestingly in the 1980s, Taiwan exported the snail meat to France. However, the discovery of parasites slowed down this market. Golden snail This golden snail is named after the colour of the shell. It is much smaller than the African snail. It is known scientifically as Pomacea bridgesii and also commonly called apple snail in the West. It was first introduced to Taiwan in 1980s as a protein food supply for the escargot industry. However, it did not become a culinary success as it carried a parasite called rat lungworm that can infect humans if not cooked thoroughly.
Golden snails from the Kalimantan Border were introduced to our highlands for food because it was supposed to be a delicious delicacy. However, what the people did not realise was this snail was enemy No. 1 for rice cultivators in several Asian countries. It was pure ignorance because golden snails were already gazetted in 1995 under the Malaysian Plant Quarantine Regulations as a pest that must be eliminated nationwide.
This snail was a destructive pest in rice fields in Thailand, Vietnam, and the Philippines. They destroy the rice plants by feeding on the shoots and laying their red eggs on rice stems, straw, and grass nearby. Control measures Nowadays we still cannot eliminate snails from the garden completely. However, there are more efficient ways to control damage to our vegetables and plants.
Picking them off by hand is easy and useful if you are able to do it at nightfall. During my childhood days, my mother would urge us to bring a torchlight or kerosene lamps to the vegetable plots near the house to collect the African snails and crush them to feed to the ducks.
Outwitting the slow but destructive snails is a challenge most gardeners have to face. Baits have been proven to be the best method and are easy to use. From simple beer traps or a solution of vinegar and water, to barriers of ash and lime, there are many tactics used as snail bait.
There are also metaldehyde-based products, which give the best control. These are reasonably priced pesticides and safe to apply without being harmful to the environment. If we don’t like to kill snails, then we have to resort to using barriers and repellents, or plant marigold flowers to keep them out.
Do send me an email if you have questions, comments, or suggestions.
Happy gardening.