Classical biological control is a sustainable tool to fight against exotic invasive weeds and insects in natural, aquatic, forest, and urban environments.
One of the agents used for the biological control of waterhyacinth, the weevil Neochetina bruchi (Photo: M. C. Hernández).
Biological invasions of weeds and insects have increased globally as a result of the world trade and movement of people. In the new environments, the invasive species usually lack their natural enemies and competitor organisms causing great ecological disturbance and economic losses. The use of natural enemies occurring in the place of origin of the pests can help to re-establish the biological balance in the invaded ecosystems. Scientifically-based classical biological control is the search of the natural enemies present in the native environment of the pests and the selection of those organisms which overcome demanding biosecurity tests. Only those organisms with high specificity are selected and later exported to quarantine facilities in the invaded regions. The successful implementation of this technique produces sustainable management of invasive species. One of the emblematic projects currently at FuEDEI is the program of biological control of waterhyacinth, Eichhornia crassipes, started in the 1960´s with the exportation of two weevils to the USA, Central America, Africa and Asia. Although these weevils have successfully controlled waterhyacinth in many regions, in others, additional biocontrol agents will be necessary to complement the effect of the weevils.