Abstract
Azolla filiculoides Lamarck (Pteridophyta: Azollaceae) (red water fern) is native to South America and was first recorded in South Africa in 1948. The lack of natural enemies and the presence of enriched waters have contributed to its establishment throughout the country where dense infestations cause severe degradation of aquatic ecosystems and limit their utilisation. The biology of A. filiculoides precludes it from being controlled manually or mechanically and herbicidal control in the aquatic environment is undesirable. Biological control is suggested as the only sustainable control method for this weed and a natural enemy, Stenopelmus rufinasus Gyllenhal (Coleptera: Curculionidae), was released for this purpose in late 1997. The weevil has established well and has caused a significant decline in the Azolla mat at a number of sites, suggesting that the weevil will be an efficient tool in the management of A. filiculoides in South Africa.
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References
Ashton, P. J., 1992. Azolla infestations in South Africa: history of the introduction, scope of the problem and prospects for management. Water Qual. Information Sheet, 7 pp.
Axelsen, S. & C. Julien, 1988. Weed control in small dams. Part II. Control of salvinia, azolla and water hyacinth. Queensland Agricultural Journal, September-October 1988: 291–298.
Buckingham, G. R. & M. Buckingham, 1981. A laboratory biology of Pseudolampsis guttata (Leconte) (Coleoptera: Chrysomelidae) on waterfern, Azolla caroliniana Willd. (Pteridophyta: Azollaceae). Coleopt. Bull. 35: 181–188.
Diatloff, G. & A. N. Lee, 1979. A new approach for control of Azolla filiculoides. Proc. 7th Asian-Pacific Weed Sci. Soc. Conf. 1979: 253–255.
Hill, M. P., 1997. The potential for the biological control of the floating aquatic fern Azolla filiculoides Lamarck (red water fern/rooivaring) in South Africa. Report to the Water Research Commission by the Plant Protection Research Institute Agricultural Research Council. WRC Report No. KV 100/97, 31 pp.
Hill, M. P., 1998a. Herbivorous insect fauna associated with Azolla species (Pteridophyta: Azollaceae) in southern Africa. Afric. Ent. 6: 370–372.
Hill, M. P., 1998b. Life history and laboratory host range of Stenopelmus rufinasus, a natural enemy for Azolla filiculoides in South Africa. BioControl 43: 215–224.
Lumpkin, T. A. & D. L. Plucknett, 1982. Azolla as a green manure: Use and Management in crop production. Westview Tropical Agriculture Series No. 5. Westview Press, Boulder, Colorado, 230 pp.
Oosthuizen, G. J. & M. M. Walters, 1961. Control of water fern with diesoline. Farming in South Africa 37: 35–37.
Steÿn, D. J., W. E. Scott, P. J. Ashton & F. S. Vivier, 1979. Guide to the use of herbicides on aquatic plants. Technical Report TR 95, Department of Water Affairs, South Africa, pp. 1–29.
Richerson, P. J. & A. A. Grigarick, 1967. The life history of Stenopelmus rufinasus (Coleoptera: Curculionidae). Ann. ent. Soc. Am. 60: 351–354.
Wagner, G. M., 1997. Azolla: A review of its biology and utilization. Bot. Rev. 63: 1–26.
Van Hove, C., C. Colot & L. Ghesquiere, 1994. From the research station to the field: the missing link. In M. Sidiki & A. Hilali (eds), Recent developments in biological nitrogen fixation research in Africa. Proceedings of the 5th International Conference of the African Association for Biological Nitrogen Fixation (AABNF), held at the Hassan II Institute of Agronomy and Veterinary Medicine (IVA), Rabat, Morocco, 14–19 September 1994: 542–547.
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Hill, M.P., Cilliers, C.J. Azolla filiculoides Lamarck (Pteridophyta: Azollaceae), its status in South Africa and control . Hydrobiologia 415, 203–206 (1999). https://doi.org/10.1023/A:1003869230591
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DOI: https://doi.org/10.1023/A:1003869230591