First report of Pomacea insularum (island apple snail) in Spain
The NPPO of Spain recently informed the EPPO Secretariat of the first report of Pomacea insularum (Gastropoda, Ampullariidae – island apple snail) on its territory. In July 2010, P. insularum was found in the left part of the Ebro delta, in the province of Tarragona (Cataluña). The snail then spread along this left part of the river and today it occurs on 613.6 ha of paddy rice fields (along a total of 130 km of irrigation channels - and along approximately 20 km of the river Ebro). For the moment, damage has been detected only in 4 hectares of rice crops, but it is considered that this invasive species has the potential to cause serious damage to rice crops in this area of Spain. Therefore, an Action Plan was implemented by the NPPO in order to control and eradicate P. insularum. The main measures included in this Action Plan are as follows: phytosanitary treatments, physical barriers to prevent further spread, removal of adult snails and egg clusters, disinfection treatments and intensive surveys. Furthermore, the possession, breeding, transport and trade of live and dead snails of two species, P. insularum and P. canaliculata (a closely related species) are prohibited across the whole Spanish territory in accordance with a Ministerial Order.
Pomacea insularum is a large snail whose shell may reach the size of an apple (hence the name). It lays egg masses in large bright pink clusters on emergent and terrestrial plants (as well as on other types of structures, concrete pillars, cisterns etc.). It feeds on a large range of submerged and emergent aquatic plants. Many pictures can be viewed on the Internet.
P. insularum has historically been confused with P. canaliculata (channeled apple snail or golden apple snail). The two species are nearly identical in appearance but molecular testing can confirm species identification. Both P. insularum and P. canaliculata inhabit slow-moving or stagnant waters in lowland marshes, irrigation canals, streams, ponds, lakes and rivers. They can develop in natural wetlands but also in irrigated crops, such as rice (Oryza sativa) and taro (Colocasia esculenta). In addition to damage to plants, Pomacea spp. are reported to be intermediate host for the rat lungworm (Angiostrongylus cantonensis), a nematode which can cause meningitis in humans. Their native range is South America (Argentina, Brazil and Bolivia). They have been introduced to Southeast Asia, where they have become serious pests of wetland crops, primarily rice, as well as invading natural wetlands. Due to the taxonomic confusion, it is probable that some of the ecological and agricultural impacts in Asia associated with P. canaliculata should be attributed to P. insularum. In the USA, the initial reports of P. canaliculata in Florida and Texas were then shown to be P. insularum. Many of these introductions have resulted from the escape (or releases) of snails from plant or animal aquaculture operations. The release of snails acquired through the pet trade probably has also occurred. Fast growth rate and high reproductive potential have most probably participated in their invasion success.
Tentative distribution lists for those two species are as follows.
- Pomacea canaliculata
EPPO region: Israel.
North America: USA (Arizona, California, Hawaii).
Caribbean: Dominican Republic.
South America: Argentina, Bolivia, Brazil, Paraguay, Uruguay.
Asia: Cambodia, China (Fujian, Guangdong, Guangxi, Hainan, Sichuan, Yunnan, Zhejiang), Indonesia (Irian Jaya, Java, Sulawesi, Sumatra), Israel, Japan (Honshu, Kyushu, Ryukyu), Korea Republic, Lao, Malaysia (Sabah), Philippines, Taiwan, Thailand, Vietnam.
Oceania: Papua New Guinea.
- Pomacea insularum
EPPO region: Israel, Spain (under eradication).
Asia: Cambodia, China, Israel, Japan (Honshu, Ryukyu), Malaysia, Philippines, Taiwan.
North America: USA (Alabama, Florida, Georgia, Hawaii, Louisiana, South Carolina, Texas).
South America: Argentina, Bolivia, Brazil.
NPPO of Spain (2011-10).
Orden ARM/2090/2011, de 22 de julio, por la que se establecen medidas provisionales de protección frente al caracol manzana "Pomacea insularum y Pomacea canaliculata". http://www.boe.es/boe/dias/2011/07/27/pdfs/BOE-A-2011-12914.pdf
Burlakova LE, Karatayev AY, Padilla DK, Cartwright LD, Hollas DN (2008) West restoration and invasive species: apple snail (Pomacea insularum) feeding on native and invasive aquatic plants. Restoration Ecology 17(3), 433-440.
Joshi RC (2005) Managing invasive alien mollusc species in rice. International Rice Research Notes 30.2, IRRI, 5-13.
Liao I-C, Liu, H-C (1989) Exotic aquatic species in Taiwan. In: de Silva SS (ed.) Exotic aquatic organisms in Asia. Proceedings of the Workshop on Introduction of Exotic Aquatic Organisms in Asia. Asian Fisheries Society. Special Publication no. 3, Manila, Philippines, pp 101-118.
Morrison WE, Hay ME (2011) Feeding and growth of native, invasive and non-invasive alien apple snails (Ampullariidae) in the United States: invasives eat more and grow more. Biological Invasions 13, 945-955.
Rawlings TA, Hayes AK, Cowie RH, Collins TM (2007) The identity, distribution, and impacts of non-native apple snails in the continental United States. BMC Evolutionary Biology 7(97). Available online: http://www.biomedcentral.com/content/pdf/1471-2148-7-97.pdf
Roll U, Dayan T, Simberloff D, Mienis HK (2009) Non-indigenous land and freshwater gastropods in Israel. Biological Invasions 11, 1963-1972.
- Freshwater gastropods of North America. Species accounts. Pomacea insularum. http://www.fwgna.org/species/ampullariidae/p_insularum.html
- Global Invasive Species database. http://www.issg.org/database/species/ecology.asp?si=1712;fr=1;sts=;lang=EN
- The apple snail website. Proceedings of the special Working Group on the golden apple snail (Pomacea spp.). (7th ICMAM, Los Baños, PH, 2003-01-25). http://applesnail.net/pestalert/conferences/icam07/
- South Carolina Department of Natural Resources. Invasive island apple snail found in Horry County (2008-06-12). http://www.dnr.sc.gov/news/yr2008/june16/june16_snail.html and http://www.dnr.sc.gov/invasiveweeds/img/snailmap.pdf
- Texas Invasives database. http://www.texasinvasives.org/animal_database/detail_print.php?symbol=15
- US Geological Survey. Non-indigenous aquatic species. Pomacea insularum. http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=2599