Biological control According to McFarland (2004), the weevil Calder and is et al. Cyrtobagus salviniae throughout the world as the method of choice for management”. The “recognized S. molesta insect has been released in 22 countries around the world including: Australia, Fiji, India, Kenya, Namibia, South Africa, Sri Lanka, USA, Zambia and Zimbabwe (Doeleman, 1990). The impacts of on are overviewed by Julien et al., 2009) with Coetzee et al., (2011) C. salviniae S. molesta giving a case study example for South Africa. Other species considered as biological control agents include the aquatic grasshopper Paulinia De Geer, the pyralid moth Guenee, the weevil acuminata Samea multiplicalis Cyrtobagus and the grass carp Val., although none of these has Hustache singularis Ctenopharyngodon idella been found to be as effective as (Oliver, 1993). A thorough review of the topic is also C. salviniae provided by Julien (2009). et al. uncertainty has been given because, in general, it is not possible to know that “Moderate” historical impacts described in the literature are still being felt in any particular geographical area. X Rating of the magnitude of impact in the current area of ☐ ☐ High Low Moderate distribution X Rating of uncertainty ☐ Moderate ☐ Low High 12.02. Impacts on ecosystem services Ecosystem service Does the IAS Short description of impact Reference impact on this Ecosystem service? Yes/No Provisioning Yes Mat formation by, and decomposition Mitchell (1969); of, can affect quality Sundaresan & S. molesta and availability (and so potentially fish (1979); Hattingh (1961); abundance). Food production may also McFarland (2004) et al. be affected by the increased risk of
Biological control According to McFarland et al. (2004), the weevil Cyrtobagus salviniae Calder and is “recognized throughout the world as the method of choice for S. molesta management”. The insect has been released in 22 countries around the world including: Australia, Fiji, India, Kenya, Namibia, South Africa, Sri Lanka, USA, Zambia and Zimbabwe (Doeleman, 1990). The impacts of C. salviniae on S. molesta are overviewed by Julien et al., 2009) with Coetzee et al., (2011) giving a case study example for South Africa. Other species considered as biological control agents include the aquatic grasshopper Paulinia acuminata De Geer, the pyralid moth Samea multiplicalis Guenee, the weevil Cyrtobagus singularis Hustache and the grass carp Ctenopharyngodon idella Val., although none of these has been found to be as effective as C. salviniae (Oliver, 1993). A thorough review of the topic is also provided by Julien et al. (2009). “Moderate” uncertainty has been given because, in general, it is not possible to know that historical impacts described in the literature are still being felt in any particular geographical area. Rating of the magnitude of impact in the current area of distribution Low ☐ Moderate ☐ High X Rating of uncertainty Low ☐ Moderate X High ☐ 12.02. Impacts on ecosystem services Ecosystem service Does the IAS impact on this Ecosystem service? Yes/No Short description of impact Reference Provisioning Yes Mat formation by, and decomposition of, S. molesta can affect quality and availability (and so potentially fish abundance). Food production may also be affected by the increased risk of Mitchell (1969); Sundaresan & (1979); Hattingh (1961); McFarland et al. (2004)
Salvinia%20molesta.docx