Biocontrol agents against eichhornia crassipes

Army Corps of Engineers estimated benefits from waterhyacinth control programs at nearly $14 million in 1965 (Gordon and Coulson, 1974). (1969) ascribed losses of $43 million in 1956 to waterhyacinth infestations in Florida, Mississippi, Alabama, and Louisiana. Fish and wildlife losses alone in the six southeastern states exceeded $4 million per year in 1947 and waterhyacinth control provided a benefit to Cost ratio of 15.3:1 (Tabita and Woods, 1962). Waterhyacinth caused annual losses (all causes) of $65 to 75 million in Louisiana during the 1940s (Gowanloch and Bajkov, 1948).

Herbicidal treatment or mechanical harvesting of waterhyacinth often damages nearby desirable vegetation.Д®xtent of losses. Higher sediment loading occurs under waterhyacinth mats due to increased detrital production and siltation. Waterhyacinth also Competes with other plants, often displacing wildlife forage and habitat (Gowanloch, 1944). Drifting mats scour vegetation, destroying native plants and wildlife habitat. The resultant lack of phytoplankton (McVea and Boyd, 1975) alters the composition of invertebrate communities (OвЂ™Hara, 1967 Hansen et al., 1971), ultimately affecting fisheries. Dense mats reduce light to submerged plants, thus depleting oxygen in aquatic communities (Ultsch, 1973).

Waterhyacinth infestations intensify mosquito problems by hindering insecticide application, interfering with predators, increasing habitat for species that attach to plants, and impeding runoff and water circulation (Seabrook, 1962).Д®cological damage. Shifting waterhyacinth mats sometimes prevent boats from reaching shore, trapping the occupants and exposing them to environmental hazards (Gowanloch and Bajkov, 1948 Harley, 1990). Infestations block access to recreational areas and decrease waterfront property values, oftentimes harming the economies of communities that depend upon fishing and water sports for revenue. Multimillion-dollar flood control and water supply projects can be rendered useless by waterhyacinth infestations (Gowanloch and Bajkov, 1948). Waterhyacinth hinders irrigation by impeding water flow, by clogging irrigation pumps, and by interfering with weirs (Penfound and Earle, 1948). Large rafts accumulate where water channels narrow, sometimes causing bridges to Collapse. Floating mats block drainage, causing flooding or preventing subsidence of floodwaters. 2), creating impenetrable barriers and obstructing navigation (Gowanloch and Bajkov, 1948 Zeiger, 1962). Waterhyacinth grows rapidly (Penfound and Earle, 1948) forming expansive colonies of tall, interwoven floating plants. A waterhyacinth infestation in southern Florida. Control with herbicides, particularly 2,4-D, is feasible, but is costly and temporary.ДЇigure 2. It is still rapidly spreading throughout Africa, where new infestations are creating life-threatening situations as well as environmental and cultural upheaval (Cock et al., 2000). It was introduced into many countries during the late 19th and early 20th centuries, where it spread and degraded aquatic ecosystems. 1), is considered one of the worldвЂ™s worst weeds (Holm et al., 1977), invading lakes, ponds, canals, and rivers. Waterhyacinth, Eichhornia crassipes (Mart.) Solms.-Laubach (Fig. In: Van Driesche, R., et al., 2002, Biological Control of Invasive Plants in the Eastern United States, USDA Forest Service Publication FHTET-2002-04, 413 p. Julien - Commonwealth Scientific and Industrial Research Organization, Indooroopilly, Australia Department of Agriculture, Agricultural Research Service, South American Biological Control Laboratory, Hurlingham, Argentina, Hill - Plant Protection Research Institute, Pretoria, South Africa,

Biocontrol agents against eichhornia crassipes