Détails de cette espèce dans New Zealand
Statut d'envahissement: Envahissant
Source: Barker and Watts 2002
Notes sur l'espèce pour cette localité:
A. fulica currently does not occur in New Zealand, however it is intercepted at NZ ports of entry quite frequently.
Notes sur la gestion de l'espèce dans cette localité:
On-going control is costly. Risk management and effects mitigation should prioritise prevention, followed by interception and treatment, early detection and rapid eradication and control efforts should aim to minimise adverse effects on native ecosystems, economic activities and public health. Prohibition of the organism and measures to support this are the first step in preventing the A. fulica from establishing in New Zealand. There is a huge risk of A. fulica being spread and introduced into new locations via trade routes. The snails ability to store sperm is a distinct advantage and could enable a founding population to form from just one individual. The majority of interceptions of A. fulica at ports of entry into Australia and New Zealand have been associated with containers. Most of the snails found were located outside of the containers. Of New Zealand's seaports Auckland had the highest number of containers landed and the most found with the snail, followed by Mt Maunganui. The large majority of giant African snail items brought into New Zealand via passengers and their luggage are declared as ornamental shells.
The Giant African Snail has been classified as an unwanted species in NZ since the Animals Act 1967 and remains classified as such under its replacement the Biosecurity Act. Several international strategies such as the World Conservation Unions Strategy on Invasive Species and the Regional Invasive Species Strategy of the South Pacific Regional Environmental Programme have also addressed the issue of the spread of A. fulica in the region. Biosecurity NZ has identified the following Pacific Island countries as high risk sources of A. fulica: Wallis and Fortuna Islands, Papau New Guinea and Vanuatu (areas where the snail has been historically intercepted from).
To improve the inspection system in New Zealand it has been suggested that these additional countries be added to the high risk status/category: American Samoa, French Polynesia, New Caledonia, Western Samoa, Philippines, Indonesia, Malaysia, Singapore, Bangladesh and South Africa. Supportive measures could include public education, access to information and penalty information, offshore certification to confirm container cleanliness and international harmonisation of biosecurity standards for containers.
New Zealand has a low level of suitability in terms of ecological requirements of the snail, primarily due to the relatively cold winter temperatures, however studies show they may survive in lower temperatures and global warming increases the likelihood of their establishment. The use of a geographic information software package (ArcMap) (based on the factors that limit the growth of A. fulica (moisture levels, temperature and land-cover type)) showed the northern and coastal regions of the North Island are the most likely areas to be colonised successfully by the giant African land snail (Cooling 2005).
Metaldehyde, methiocarb, thidicarb and iron chelate are all registered for use in New Zealand. However, indigenous New Zealand molluscs may be at particular risk to chemical control via baiting. DOC (2002) believe it is likely that Placostylus, Succinea and Archeai and some members of Charpoidae and Puntidae would be likely to eat the baits. Iron chelates could also affect some molluscs as well as isopods, crustacea and arachnida.
Much effort and money can be spent on control and eradication of the snail by commercial businesses, private individuals and the Government. The use of biological control agents is risky and has produced a number of undesirable effects overseas including the extinction of native molluscs. Chemical controls have the potential to affect native species, particularly native molluscs and are unpopular with the public.
Notes sur la localité:
New Zealand has may unique species that evolved during 80 million years of isolation and many have been devastated by the combination of alien species and habitat destruction (Parliamentary Commissioner for the Environment 2000). There are thirty species of alien molluscs established in New Zealand (Barker and Watts 2002).
Agricole: A. fulica could impact horticulture, agriculture, forestry and home gardens in New Zealand. Of the more than 500 species of plants it feeds on, the following plants are found in New Zealand: bananas (Musa spp.), Asplenium spp., Bougainvillea spp., cabbage and Cruciferae, cactus (Opuntia and Cereus spp.), Canna spp., carrots, capsicums, Compositae, Tagetes spp., Citrus spp., Cucurbitacea, Daphlia spp., eucalyptus spp., ferns, figs, hibiscus, Impatiens balsamina, jasmine, Leguminosae, lettuce, lilies, oleander, orchids, passionfruit species, potato, Rosa species, spinach, Solanaceae (egg plant, chillies and tomato), taro species, tabacco and yam (Raut and Barker 2002; Mead 1961, Srivastava 1992, Animal and Plant Health Inspection Service 2005, in Cooling 2005).
Autre: The snail has the potential to out-compete and displace native species, to alter the community composition, to modify the habitat and to introduce fungi and parasites into native ecosystems.
Économique/Subsistance: New Zealand's horticultural exports increased from approximately $1 300 000 in 1997 to approximately $1 800 000 in 2000 (Statistics New Zealand 2004, in Cooling 2005) and this sector would be one of the most likely, along with the nursery industry to be affected.
Réduction de la biodiversité indigène: Achatina fulica is known to eat Asplenium, Phorium and Cordyline snails (Venette & Larson 2004, in Cooling 2005). There are 16 native Asplenium species in New Zealand (Dawson and Lucus 2000, in Cooling 2005). A. fulica is also likely to cause significant harm to native plants (Animal and Plant Inspection Service 2005, in Cooling 2005).
Dernière mise à jour: 14/03/2006