Biological control of Salvinia molesta in South Africa revisited

Martin, Grant D; Coetzee, Julie A; Weyl, Philip S R; Parkinson, Matthew C; Hill, Martin P

Title: Biological control of Salvinia molesta in South Africa revisited
Creator: Martin, Grant D
Creator: Coetzee, Julie A
Creator: Weyl, Philip S R
Creator: Parkinson, Matthew C
Creator: Hill, Martin P
Date Issued: 2018
Date: 2018
Type: text
Type: article
Identifier: http://hdl.handle.net/10962/103878
Identifier: vital:32318
Identifier: https://doi.org/10.1016/j.biocontrol.2018.06.011
Description: The aquatic weed Salvinia molesta D.S. Mitch. (Salviniaceae) was first recorded in South Africa in the early 1900s, and by the 1960s was regarded as one of South Africa’s worst aquatic weeds. Following the release of the weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) in 1985, the weed is now considered under successful biological control. However, the post-release evaluation of this biological control programme has been ad hoc, therefore, to assess the efficacy of the agent, annual quantitative surveys of South African freshwater systems have been undertaken since 2008. Over the last ten years, of the 57 S. molesta sites visited annually in South Africa, the weevil has established at all of them. Eighteen sites are under successful biological control, where the weed no longer poses a threat to the system and 19 are under substantial biological control, where biological control has reduced the impact of the weed. Since 2008, the average percentage weed cover at sites has declined significantly from 51–100% cover to 0–5% cover in 2017 (R2 = 0.78; P < 0.05). Observations of site-specific characteristics suggest that biological control is most effective at small sites and more difficult at larger and shaded sites. Our findings show that S. molesta remains under good biological control in South Africa, however, some sites require intermittent strategic management, such as augmentative releases of C. salviniae.
Format: 7 pages
Format: pdf
Language: English
Relation: Biological control
Relation: Martin, G.D., Coetzee, J.A., Weyl, P.S.R., Parkinson, M.C. and Hill, M.P., 2018. Biological control of Salvinia molesta in South Africa revisited. Biological control, 125, pp.74-80.
Relation: Biological control volume 125 74 80 October 2018 1090-2112
Rights: Authors
Rights: Use of this resource is governed by the terms and conditions of the Elsevier Terms and Conditions Statement (https://www.elsevier.com/legal/elsevier-website-terms-and-conditions)

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