Snails entering new territory

PATHANAMTHITTA: The Giant African snails are spreading fast in the district, after being confined to a few wards in the Konni grama panchayat limits since their first sighting in 2008.

People fear that the snails will pose a health hazard and will have an impact on the ecosystem. They complain that effective steps have not been taken to contain the mollusc menace, despite repeated warnings from experts and environmentalists.

After the monsoon set in, the snails have been spreading to the nearby panchayats of Pramadom, Chenneerkara, and Thumpamon and in certain parts of the Adoor and the Pathanamthitta municipal areas, especially the Kumbazha market.

These nocturnal creatures have been causing much harm to the tapioca, papaya, and rubber crops and other vegetation in Konni. They feed on tender leaves of coconut palms.

The Kerala Forest Research Institute (KFRI), after a study on the snail menace in Konni eight months ago, had stressed the need to eradicate them before summer by the time they go into hibernation. The study report was submitted to the Ombudsman for Local Self-Government Institutions.

People are now pinning their hopes on Health Minister Adoor Prakash, who represents the Konni constituency, says Ratheesh Babu, a social activist who has been actively involved in the snail-eradication campaign.

After the first sighting in June 2008, the snails have multiplied fast. Experts say that a snail lays as many as 400 eggs at a time and at least 380 of them are hatched. The snails come out of their daytime hideouts, such as wet burrows on trees and rocks, during night and move in clusters.

Aby Abraham and K.M. Koshy, members of an Agriculture Department team that had visited the snail-infested areas of Konni in October 2010, were of the opinion that cleanliness and sanitation should be given top priority in keeping creatures such as snails from the courtyards and surroundings of houses. The snails they found in Konni weighed 700-800 grams. The team was awestruck witnessing the snails feeding on the walls of a building. The snails feed on vegetation and walls as their shells require a good amount of calcium.

The expert team opined that steps should be taken to launch cultivation on all lands lying fallow in the affected area as wet fallow lands were the best breeding grounds of such creatures. The team felt the need to adopt chemical control methods to combat such a large-scale menace.

The KFRI study report said the practice of using metaldehyde and common salt to kill the snails would have an adverse impact on terrestrial and aquatic fauna and excessive use of common salt would alter the soil chemistry, making it unfit for agriculture.

Snails should not be consumed as it was an intermediate vector of the rat lungworm which caused eosinophilic meningitis in humans, besides playing host to Aeromonas hydrophila, a pathogen found in hosts with weak immune systems, the report said.

It suggested thorough checking of vehicles moving out from the infested area to make sure that snails were not accidentally transported to new locations.

The report said the snail menace had been reported from the districts of Thiruvananthapuram, Pathanamthitta, Kollam, Idukki, Ernakulam, Palakkad, Kozhikode, Kannur, and Kasaragod. However, the infestation in Konni was high, requiring urgent efforts to reduce its numbers as the wells in the area were contaminated by snail excreta.

Source: The Hindu 29-06-2011

New cactus species poses a threat

KOCHI: A thorny invader is spreading its roots in some parts of Kerala and posing a threat to the local flora and fauna. Cylindropuntia ramosissima, a species of cactus, believed to be a native of Northern Mexico, has been located at Attappady area of Palakkad district.

A three-member team of the Kerala Forest Research Institute, Thrissur, consisting of K. V. Sankaran, director of the institute, T. V. Sajeev, scientist and T. A. Suresh, research scholar, indentified the weed during a survey conducted across the State for invasive weeds and trees.

The spiny weed is mainly seen in the dry areas of south western United States and northern Mexico.

Researchers say the weed is used as a hedge plant to protect agricultural land from wild animals, and came into the State from Tamil Nadu.

The hedges of this spiny plant can even stop marauding wild elephants from attacking farm lands. It is believed that the species might have been introduced in the country as a garden plant.

Though the distribution of the plants is very restricted, people from other parts of the State were found collecting them to be used as hedge plants elsewhere. Local population has been sensitised about the risk factors involved, and the need to restrict its spread, said Dr. Sajeev.

The researchers believe that the plant was introduced in Attappady area nearly a decade ago as the plants found in the area are almost seven-metre tall.

Local people reported that the thorns were very poisonous. The reverse barbs on the thorns make it easy to grab on, and hence it is difficult to remove once it pierces through the skin.

This weed spreads in open areas, including the flanks of the roads replacing native flora and fauna. Vegetative propagation is the main source of reproduction, researchers said.

Source: The Hindu, 20-11-2010

Eradicate snails before summer, suggests expert

KOCHI: The eradication of Giant African Snails should be completed before summer as they would go into hibernation by the time, an expert report has said.

Once they hibernate, they cannot be lured out with baits, said a report by T.V. Sajeev, an entomologist of the Forest Health Division of the Kerala Forest Research Institute, Peechi. The report was submitted to the Ombudsman for local self-government institutions. The institute was asked to study the infestation of the snail in Kerala, particularly in Konni.

The mollusc can go to summer sleep up to three years during extreme drought, sealing itself into its shell secretion of a cal carious compound that dries on contact with air.

The practice of using metaldehyde, a pesticide, and common salt to kill the snail will leave adverse impact on terrestrial and aquatic fauna. Excessive use of common salt alters the soil chemistry making it unfit for agriculture, the report said.

Snails should not be consumed as it is an intermediate vector of the rat lungworm which causes eosinophilic meningitis in humans. It also plays host to aeromonas hydrophila, a pathogen found in hosts with weak immune system.

Vehicles moving out from the area should be thoroughly checked for making sure that it is not accidentally transported to new locations. The snails collected using protective gloves can be destroyed using tobacco decoction and copper sulphate mixture. Baits can be set in the evenings using cabbage leaves, it was suggested.

The mollusc, Achatina Fulica Bowtich, is a native of coastal East Africa. It is an invasive species which has escaped from its naturally distributed area and invaded many parts of the world.

The Global Invasive Species Database managed by the Invasive Species Specialist Group of the International Union for Conservation of Nature has ranked it second in the list of world's 100 worst invaders.

Even though the creatures thrive in humid and warm conditions, they are highly adaptable to dry and cooler climates. They hibernate 10 to 15 cm deep in soft soil during less favourable conditions for up to one year, the report said.

The snails might have reached Kerala in the 1970s. Its presence was first reported from Palakkad. At present, most of the districts, including Thiruvananthapuram, Pathanamthitta, Kollam, Idukki, Ernakulam, Palakkad, Kozhikode, Kannur and Kasargod, have at least one location with snail infestation, it was reported.

The infestation in Konni is quite high requiring urgent efforts to reduce its population. The wells in the area are contaminated by the snail excreta. Vomiting tendency, giddiness and irritation were reported by the people who handled the snail. Its empty shells have become breeding sites of mosquitoes too, it was reported.

Source: The Hindu, 9-11-2010

Snail menace: experts visit Konni

PATHANAMTHITTA: A team of experts from the Kerala Agricultural University and the Agriculture Department visited the Giant African Snail-infested areas of Konni grama panchayat on Tuesday following reports of the creeping creatures feeding on vegetation, posing threat to agriculture.

The Giant African Snails have been thriving in Konni for the last two years. People were complaining of destruction of vegetable plants, coconut trees, cash crops etc. by snails. These creeping, greasy creatures feed on all kinds of plants.

The expert team comprised T.M. Kurien, head of KAU Agriculture Research Station in Thiruvalla; Aby Abraham, Assistant Director of Agriculture; K.M. Koshy, Deputy Director of Agriculture; Ambikadevi, entomologist, and Sajeena, plant pathologist.

The team members collected snail specimens from their daytime hideouts for examination. Dr. Abraham and Dr. Koshy told The Hindu that hygiene should be given top priority to keep off creatures like snails.

Dr. Abraham said the snails they found were giant in size weighing 700 to 800 grams. They fed on vegetation and walls of buildings as they required a good amount of calcium for their shell. He said spraying of copper sulphate-tobacco mixture was an organic way of snail eradication.

The team also felt the need to adopt chemical control methods to combat such a large-scale snail menace in Konni. Metaldehide would be effective in this regard. Steps should be taken to launch cultivation in all lands lying fallow in the affected areas as wet fallow lands were found to have been the best breeding grounds of such creatures.

Dr. Abraham said the team would submit its report to the Agriculture Department soon so that the department could release funds for snail-eradication in Konni and surrounding areas on a war-footing.

The Source: The Hindu, 6-10-2010