Biological control is effective on large areas of water hyacinth but may take years to achieve satisfactory control.
Four insect species have been introduced from South America and released by CSIRO since 1975. The 2 weevil species Neochetina eichhorniae and Neochetina bruchi, and the 2 moth species Niphograpta albiguttalis and Xubida infusella are present in Queensland.
To establish an effective breeding population of biological control agents, infested plants should be placed in an area where water hyacinth is concentrated. Your local government office or Biosecurity Queensland can help you with protocols and more information.
The presence of these biocontrol agents does not relieve landholders of their responsibility under Queensland legislation to control declared plants.