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University of Arizona SWES

University of Arizona SWES. Enue E. Sicairos Ruelas October 6 th 2005. A quiet enemy: Salvinia molesta. Overview. Salvinia molesta ( Giant Salvinia, Kariba weed, African pyle) is a free floating fern native to southeastern Brazil.

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University of Arizona SWES

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  1. University of ArizonaSWES Enue E. Sicairos Ruelas October 6th 2005 A quiet enemy: Salvinia molesta

  2. Overview • Salvinia molesta (Giant Salvinia, Kariba weed, African pyle) is a free floating fern native to southeastern Brazil. • Dense mats affect the growth of native vegetation, wildlife and degrade water quality. • Over the past 70 years, S. molesta has spread to tropical and subtropical regions The Nature Conservancy, 2000 A quiet enemy: Salvinia molesta

  3. Taxonomic classification Salvinia molesta belongs to a monogeneric family Salviniaceae S. auriculata S. herzogii S. biloba S. molesta S. auriculata complex A quiet enemy: Salvinia molesta

  4. Morphology and reproduction Hairy floating leaves Root like submerged leaf Weed management ,2003 • Great morphological variation depending on the conditions of habitat • Vegetative Reproduction A quiet enemy: Salvinia molesta

  5. Malaysia Cuba Sri Lanka South America India Australia Philippines Geographical distribution Native from Southeastern Brazil A quiet enemy: Salvinia molesta

  6. Presence in the United States 1990 - S. molesta was introduced as an ornamental plant 1995 - Outside of cultivation in private pond in South Carolina 1998 - New outbreaks were registered in Texas 1999 - Invaded over 50 localities in southern tier states A quiet enemy: Salvinia molesta

  7. Presence in Mexico Entered for first time in 2003 through the Colorado river ag.arizona.edu/OALS/ ALN/aln44/milich11.html A quiet enemy: Salvinia molesta

  8. Ecological impacts Detrimental • Salvinia mats depress oxygen concentrations. • Mats blocks the access to drinking water by humans, domestic stock and wild life. • Clog irrigation and drainage canals. • Prevents water use for recreational activities, such as swimming, boating, water skiing, and fishing USGS,2005 A quiet enemy: Salvinia molesta

  9. Ecological impacts Beneficial • S. Molesta hasbeen used as a compost and mulch • As a supplement to food for livestock insome Asian countries A quiet enemy: Salvinia molesta

  10. Management options A) Chemical control • 1940’s emulsifiable oils containing pentachlorophenol was used in Sri Lanka. • Paraquat and sodium arsenite have been used to but only provide short term control. B) Physical control • Manual removal has been successful in controlling S. molesta in the initial, uncrowded stage of population development. A quiet enemy: Salvinia molesta

  11. Management options C) Biological control Use of the weevil Cyrtobagous salviniae Biology • Adults typically reside on or beneath the fronds • Eggs are laid individually in cavities formed by the female’s feeding activity Damage • Adults will feed on the fronds, leaving small irregularly shaped holes • The plants initially turn brown in small patches until entire mat appears brown and begins to sink Weevil Cyrtobagous salviniae A quiet enemy: Salvinia molesta

  12. Conclusion • Invasive alien plant and animal species increasingly threaten biodiversity and bring economic losses • Maybe, one day, we will learn how to respect Mother Nature, but in the mean time, we have to find a way to bring equilibrium again A quiet enemy: Salvinia molesta

  13. Questions? A quiet enemy: Salvinia molesta

  14. Yummy! A quiet enemy: Salvinia molesta

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