Control of Waterhyacinth by Neochetina bruchi (Coleoptera: Curculionidae: Bagoini) in Argentina

Abstract

The first case of biological control of waterhyacinth, Eichhornia crassipes (Mart.) Solms, by the weevil Neochetina bruchi Hustache is reported from the Dique Los Sauces reservoir in La Rioja Province, Argentina. Four years after introduction of N. bruchi , its population had increased to 3.5 adults per plant; waterhyacinth was reduced from the usual 50% coverage of the water surface to only 10 to 15% coverage, and 2 years later to only 4 to 8% coverage.