Biodiversity & Conservation

, Volume 5, Issue 10, pp 1231–1252 | Cite as

A tale of two snails: is the cure worse than the disease?

  • L. Civeyrel
  • D. Simberloff

The giant African snail, Achatina fulica, has been introduced to many parts of Asia as well as to numerous islands in the Indian and Pacific Ocean, and has recently reached the West Indies. It has been widely decried as a disaster to agricultural economies and a threat to human health, leading to a clamor for the introduction of biological control agents. In fact, the lasting impact on agriculture may not be severe, and the human health risk is probably minor. This snail can be an aesthetic atrocity and a nuisance in other ways, however. Wherever A. fulica has achieved high densities, it has subsequently undergone a striking decline. Although this decline has been attributed to introduced predators, there is little evidence for this hypothesis; instead, epizootic disease seems to be at least part of the cause. However, the introduced predators, especially a New World snail, Euglandina rosea, have wrought havoc with the native land snails of many islands. They have already caused many extinctions and will almost certainly cause others. This predator was introduced by government agencies in many areas despite warnings from competent biologists that the effects could be disastrous. Pressures for such actions may become overwhelming in the face of a highly visible invasion, despite policies that should mandate extreme caution.


Achatina fulica biological control Euglandina rosea extinction introduced species non-indigenous species predation 


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  1. Boettger, C.R. (1947) Einschleppung von Schnecken mit Bananensendungen nach Deutschland. Arch. f. Mollusk. 76, 65–7.Google Scholar
  2. Carruthers, R.I. and Onsager, J.A. (1993) Perspective on the use of exotic natural enemies for biological control of pest grasshoppers (Orthoptera: Acrididae). Environm. Entomol. 22, 885–903.Google Scholar
  3. Center, T.D., Frank, J.H. and Dray, F.A.Jr. (1995) Bioloigical invasions: stemming the tide in Florida. Florida Entomologist 78, 45–55.Google Scholar
  4. Chen, D.-N. (1991) A study on Achatina fulica (Fer.) in China (classification, distribution and artificial breeding). Proc. Tenth Internat. Malacol. Congr. 1, 297–301.Google Scholar
  5. Cheng, T.C. and Alicata, J.E. (1965) On the modes of infection of Achatina fulica by the larvae of Angiostrongylus cantonensis. Malacologia 2, 267–74.Google Scholar
  6. Clarke, B., Murray, J. and Johnson, M.S. (1984) The extinction of endemic species by a program of biological control. Pac. Sci. 38, 97–104.Google Scholar
  7. Colman, P.H. (1977) An introduction of Achatina fulica to Australia. Malacological Review 10, 77–8.Google Scholar
  8. Colman, P.H. (1978) An invading giant. Wildlife in Australia 15, 46–7.Google Scholar
  9. Cook, A. (1985a) Functional aspects of trail following by the carnivorous snail Euglandina rosea. Malacologia 26, 173–81.Google Scholar
  10. Cook, A. (1985b) The organisation of feeding in the carnivorous snail Euglandina rosea. Malacologia 26, 183–9.Google Scholar
  11. Cook, A. (1989) Factors affecting prey choice and feeding technique in the carnivorous Euglandina rosea Ferussac. J. Molluscan Studies 55, 469–77.Google Scholar
  12. Cowie, R.H. (1992) Evolution and extinction of Partulidae, endemic Pacific island land snails. Phil. Trans. Royal Soc. Lond. B 335, 167–91.Google Scholar
  13. Dahlsten, D.L. (1986) Control of invaders. In Ecology of Biological Invasions of North America and Hawaii (H.A. Mooney and J.A. Drake, eds) pp. 275–302, New York: Springer-Verlag.Google Scholar
  14. Davis, C.J. and Butler, G.D. (1964) Introduced enemies of the giant African snail, Achatina fulica Bowdich, in Hawaii. Proc. Hawaiian Ent. Soc. 18, 377–89.Google Scholar
  15. Dean, W.W., Mead, A.R. and Northey, W.T. (1970) Aeromonas liquefaciens in the giant African snail, Achatina fulica. J. Invert. Pathology, 16, 346–51.Google Scholar
  16. DeLoach, C.J. (1991) Past successes and current prospects in biological control of weeds in the United States and Canada. Natural Areas J. 11, 129–42.Google Scholar
  17. de Winter, A.J. (1988) Achatina fulica in West Africa. Basteria 52(1–3): 2.Google Scholar
  18. Elton, C.S. (1958) The Ecology of Invasions by Animals and Plants. London: Chapman & Hall.Google Scholar
  19. Etienne, J. (1973) Lutte biologique contre les escargots nuisibles aux cultures. Rapport Institut de Recherche Agronomique Tropical et des Cultures Vivrières Réunion: 71–3.Google Scholar
  20. Freeland, W.J. (1986) Populations of cane toad, Bufo marinus, in relation to time since colonization. Austr. Wildl. Res. 13, 321–9.Google Scholar
  21. Freeland, W.J., Delvinqueir, B.L.J. and Bonnin, B. (1986) Food and parasitism of the cane toad, Bufo marinus, in relation to time since colonization. Austr. Wildl. Res. 13, 489–99.Google Scholar
  22. Gascoigne, A. (1994) The biogeography of land snails in the islands of the Gulf of Guinea. Biodiver. Conserv. 3, 794–807.Google Scholar
  23. Gerlach, J. (1989) A report on the status of Euglandina rosea in Seychelles. Papustyla, No. 3/89, pp. 2–5.Google Scholar
  24. Gonzalez, D. and Gilstrap, F.E. (1992) Foreign exploration: assessing and prioritizing natural enemies and consequences of preintroduction studies. In Selection Criteria and Ecological Consequences of Importing Natural Enemies. (W.C. Kauffman and J.E. Nechols eds). pp. 51–70, Lanham, Maryland: Entomological Society of America.Google Scholar
  25. Griffiths, O., Cook, A. and Wells, S.M. (1993) The diet of the introduced carnivorous snail Euglandina rosea in Mauritius and its implications for threatened island gastropod fauna. J. Zool. (Lond.) 229, 79–89.Google Scholar
  26. Groombridge, B. (ed.) (1992) Global Biodiversity: Status of the Earth's Living Resources. London: Chapman & Hall.Google Scholar
  27. Hadfield, M.G. (1986) Extinction in Hawaiian Achatinelline snails. Malacologia 27, 67–81.Google Scholar
  28. Hadfield, M.G., and Miller, S.E. (1992) Alien predators and decimation of endemic Hawaiian tree snails. Pac. Sci. 46, 395.Google Scholar
  29. Hadfield, M.G., Miller, S.E. and Carwile, A.H. (1993) The decimation of endemic Hawaiian tree snails by alien predators. Amer. Zoologist 33, 610–22.Google Scholar
  30. Hadfield, M.G. and Mountain, B.S. (1981) A field study of a vanishing species, Achatinella mustelina (Gastropoda: Pulmonata), in the Waianae Mountains of Oahu. Pac. Sci. 34, 345–58.Google Scholar
  31. Hart, A.D. (1978) The onslaught against Hawaii's tree snails. Natural History 87, 46–57.Google Scholar
  32. Herklots, G.A.C. (1948) Giant African snail Achatina fulica. Fer. Food Flowers 1, 1–4.Google Scholar
  33. Hokkanen, H. and Pimentel, D. (1984) New approach for selecting biological control agents. Can. Entomol. 116, 1109–21.Google Scholar
  34. Hokkanen, H., and Pimentel, D. (1989) New associations in biological control: theory and practice. Can. Entomol. 121, 829–40.Google Scholar
  35. Hopper, D.R. and Smith, B.D. (1992) Status of tree snails (Gastropoda: Partulidae) on Guam, with a resurvey of sites studied by H.E. Crampton in 1920. Pac. Sci. 46, 77–85.Google Scholar
  36. Howarth, F.G. (1983) Classical biological control: Panacea or Pandora's Box? Proc. Hawaiian Entomological Soc. 24, 239–44.Google Scholar
  37. Howarth, F.G. (1991) Environmental impacts of classical biological control. Annu. Rev. Entomol. 36, 485–509.Google Scholar
  38. Kaburaki, T. (1940) Further notes on the effect of some exotic animals upon the fauna of Japan. Proc. Sixth Pacific Sci. Congr. 4, 229–30.Google Scholar
  39. King, C.M. 1990. The Handbook of New Zealand Mammals. Auckland: Oxford University Press.Google Scholar
  40. Kinzie, R.A.III (1992) Predation by the introduced carnivore snail Euglandina rosea (Ferrusac) on endemic aquatic lymnaeid snails in Hawaii. Biol. Conserv. 60, 149–55.Google Scholar
  41. Lake, P.S. and O'Dowd, D.J. (1991) Red crab in rain forest, Christmas Island: Biotic resistance to invasion by an exotic snail. Oikos 62, 25–59.Google Scholar
  42. Lambert, M. (1974) L'escargot géant africain Achatina fulica dans les iles du Pacifique. Bulletin de la Commission du Pacifique Sud 24, 37–42.Google Scholar
  43. Leader-Williams, N. (1988) Reindeer on South Georgia. Cambridge: Cambridge University Press.Google Scholar
  44. Lockwood, J.A. (1993) Environmental issues involved in biological control of rangeland grasshopper (Orthoptera: Acrididae) with exotic agents. Environm. Entomol. 22, 503–18.Google Scholar
  45. Mead, A.R. (1955a) The proposed introduction of predatory snails into California. The Nautilus 69, 37–9.Google Scholar
  46. Mead, A.R. (1955b) The giant African snail in Ceylon. The Ceylon Forester 2, 47–50.Google Scholar
  47. Mead, A.R. (1959) The appearance of the giant African snail in Arizona. Proc. Hawaiian Ent. Soc. 17, 85–6.Google Scholar
  48. Mead, A.R. (1961) The Giant African Snail. A Problem in Economic Malacology. Chicago: University of Chicago Press.Google Scholar
  49. Mead, A.R. (1963a) Disease, decline, and predation in the giant African snail population in Hawaii. Annu. Rept. Amer. Malacol. Union, 22.Google Scholar
  50. Mead, A.R. (1963b) A flatworm predator of the giant African snail Achatina fulica in Hawaii. Malacologia 1, 305–11.Google Scholar
  51. Mead, A.R. (1971) Status of Achatina and Rumina in the United States. The Biologist 53, 112–17.Google Scholar
  52. Mead, A.R. (1971) Economic Malacology: with Particular Reference to Achatina fulica. In Pulmonates. (V. Fretter, J. Fretter and J. Peake, eds) Vol. 2B. London: Academic Press.Google Scholar
  53. Mead, A.R. and Palcy, L. (1992) Two giant African land snail species spread to Martinique, French West Indies. The Veliger 35, 74–7.Google Scholar
  54. Muniappan, R. (1983) Giant African snail enemy in Guam. Biocontrol News Inf. 4, 196.Google Scholar
  55. Muniappan, R. (1987) Biological control of the giant Africn snail Achatina fulica Bow. in the Maldives. FAO Plant Prot. Bull. 35, 127–33.Google Scholar
  56. Muniappan, R., Duhamel, G., Santiago, R.M. and Acay, D.R. (1986) Giant African snail control in Bugsuk Island, Philippines, by Platydemus manokwari. Oleagineux 41, 183–6.Google Scholar
  57. Murray, E. (1993) The sinister snail. Endeavour (New Series) 17, 78–83.Google Scholar
  58. Murray, J., Murray, E., Johnson, M.S. and Clarke, B. (1988) The extinction of Partula on Moorea. Pac. Sci. 42, 150–3.Google Scholar
  59. Nechols, J.R., Kauffman, W.C. and Schaefer, P.W. (1992) Significance of host specificity in classical biological control. In Selection Criteria and Ecological Consequences of Importing Natural Enemies. (W.C. Kauffman and J.E. Nechols, eds) pp. 41–52. Lanham, Maryland: Entomological Society of America.Google Scholar
  60. Nishida, T., and Napompeth, B. (1975) Effect of age-specific predation on age distribution and survival of the giant African snail Achatina fulica. Proc. Hawaiian Ent. Soc. 22, 119–23.Google Scholar
  61. Norton, B.G. (1987) Why Preserve Natural Variety? Princeton, New Jersey: Princeton University Press.Google Scholar
  62. O'Brien, S.J., Roelke, M.E., Marker, L., Newman, A., Winkler, C.A., Meltzer, D., Colly, L., Evermann, J.F., Bush, M. and Wildt, D.E. (1985) Genetic basis for species vulnerability in the cheetah. Science 227, 1428–34.Google Scholar
  63. OTA (1993) Harmful Non-Indigenous Species in the United States. OTA-F-565. US Congress, Office of Technology Assessment. Washington, DC: US Government Printing Office.Google Scholar
  64. Palcy, L. and Mead, A.R. (1993) Les deux redoutables escargots géants africains à la Martinique. Phytoma-La Défense des Végétaux 449, 48–50.Google Scholar
  65. Pemberton, C.E. (1938) The giant African snail Achatina fulica discovered in Hawaii. Hawaiian Planters' Rec. 42, 135–40.Google Scholar
  66. Pilsbry, H.A. and Bequaert, J.C. (1927) The aquatic mollusks of the Belgian Congo with a geographical and ecological account of Congo malacology. Bull. Amer. Mus. Nat. Hist. 53, 69–602.Google Scholar
  67. Pointier, J.-P. and Blanc, C. (1985) Achatina fulica en Polynesie Française. Malakologische abhandlungen 11, 1–15.Google Scholar
  68. Ranaivosoa, H. (1971) Lutte biologique contre les escargots phytophages à Madagascar et aux Comores. L'Agronomie Tropicale, Série 3 26, 341–7.Google Scholar
  69. Raut, S.K. and Ghose, K.C. (1984) Pestiferous Land Snails of India. Zoological Survey of India, no. 11, pp. 1–151 Calcutta: Bani Press.Google Scholar
  70. Shenon, P. (1995) In Vietnam, the snails dine regally. New York Times, May 17, 1995, p. A9.Google Scholar
  71. Simberloff, D. (1981) Community effects of introduced species. In Biotic Crises in Ecological and Evolutionary Time. (M.H. Nitecki, ed.) pp. 53–81. New York: Academic Press.Google Scholar
  72. Simberloff, D. (1992) Conservation of pristine habitats and unintended effects of biological control. In Selection Criteria and Ecological Consequences of Importing Natural Enemies (W.C. Kauffman and J.E. Nechols, eds) pp. 103–17. Lanham, Maryland: Entomological Society of America.Google Scholar
  73. Simberloff, D. (1995) Introduced species. Encyclopedia of Environmental Biology, Vol. 1. San Diego: Academic Press.Google Scholar
  74. Simberloff, D. and Stiling, P. (1996) Risks of species introduced for biological control. Ecology, in press.Google Scholar
  75. Simmonds, F.J. and Hughes, I.W. (1963) Biological control of snails exerted by Euglandina rosea (Ferussac) in Bermuda. Entomophaga 8, 219–22.Google Scholar
  76. Smith, C.W. (1992) Management of alien species in natural areas of Oceania. Pac. Sci. 46, 386–7.Google Scholar
  77. SPVM and FDGDC (1990) Compte-rendu de la campagne de lutte contre les escargots géants d'Afrique au Morne Rouge et à Saint Esprit. Service de la Protection Végétaux de la Martinique et Fédération Départementale des Groupements de Défense des Cultures. 11 pp.Google Scholar
  78. SPVM and FDGDC (1991) Rapport de lutte généralisée Achatine. Service de la Protection Végétaux de la Martinique et Fédération Départementale des Groupements de Défense des Cultures. 6 pp.Google Scholar
  79. Solem, A. (1968) Why who lives where. Basic distribution of non-marine mollusks. Proceedings of the Symposium on Mollusca. Part I, pp. 231–47. Mandapam Camp, India: Marine Biological Association of India.Google Scholar
  80. Solem, A. (1984) A world model of land snail diversity and abundance. In World-wide Snails, Biogeographical Studies of Non-marine Molluscs. (A. Solem and A.C.van Bruggen, eds) pp. 6–22. Leyden: E.J. Brill and W. Backhuys.Google Scholar
  81. Solem, A. (1990) How many Hawaiian land snail species are left? And what we can do for them. Bishop Museum Occ. Pap. 30, 27–40.Google Scholar
  82. Sproul, A.N. (1983) Christmas Island snail search. J. Agric. (W. Austr.) 3, 94–6.Google Scholar
  83. Takeuchi, K., Koyano, S. and Numazawa, K. (1991) Occurrence of the giant African snail in the Ogasawara (Bonin) Islands, Japan. Micronesica (Suppl.) 3, 109–16.Google Scholar
  84. Tillier, S. (1982) Production et cycle reproducteur de l'escargot Achatina fulica Bowdich 1822 en Nouvelle Calédonie. Haliotis 12, 111–22.Google Scholar
  85. Tillier, S. (1992) Introduced land snails in New Caledonia: A limited impact in the past, a potential disaster in the future. Pac. Sci. 46, 396–7.Google Scholar
  86. Tillier, S. and Clarke, B.C. (1983) Lutte biologique et destruction du patrimoine génétique: le cas des mollusques gastéropodes pulmonés dans les territoires français du Pacifique. Génét. Sél. Evol. 15, 559–66.Google Scholar
  87. Van Bruggen, A.C. (1980) Notes on the African element among the terrestrial molluscs of Madagascar. Haliotis 10, 32.Google Scholar
  88. Van Bruggen, A.C. (1987) Achatina fulica in Morocco, North Africa. Basteria 51, 66.Google Scholar
  89. van den Bosch, R. and Messenger, P.S. (1973) Biological Control. New York: Intext.Google Scholar
  90. Van der Schalie, H. (1969) Man meddles with nature-Hawaiian style. The Biologist 51, 136–46.Google Scholar
  91. Wallace, G.D. and Rosen, L. (1969) Studies on eosinophilic meningitis. V. Molluscan hosts of Angiostrongylus cantonensis on Pacific islands. American Journal of Tropical Medicine and Hygiene 18, 206–16.Google Scholar
  92. Waterhouse, D.F. and Norris, K.R. (1987) Achatina fulica Bowdich. Mollusca: Achatinidae Giant African Snail. In Biological Control (D.F. Waterhouse and K.R. Norris, eds) pp. 267–73. Melbourne: Inkata Press.Google Scholar
  93. Watson, B.J. (1985) The giant African snail in Australia. Pest or nuisance. Queensland Agricultural J. 111, 7–10.Google Scholar
  94. Wells, S.M. (1988) Snails going extinct at speed. New Scientist 117, 46–8.Google Scholar
  95. Wells, S.M., Pyle, R.M. and Collins, N.M. (1983) The IUCN Invertebrate Red Data Book. Gland. Switzerland, and Cambridge, UK: International Union for the Conservation of Nature.Google Scholar
  96. Williams, F.X. (1953) Some natural enemies of snails of the genus Achatina in East Africa. Proc. 7th Pacific Sci. Congress, 1949, 4, 277–8.Google Scholar
  97. Williams, R.N. (1987) Alien birds on Oahu: 1944–1985. Elepaio 49, 87–92.Google Scholar

Copyright information

© Chapman & Hall 1996

Authors and Affiliations

  • L. Civeyrel
    • 1
  • D. Simberloff
    • 2
  1. 1.Laboratoire de Palynologie ISEM and EPHE PhytomorphologieUniversité Monipellier IlMontpellier cedex 05France
  2. 2.Department of Biological ScienceFioride State UniversityTallahasseeUSA

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