How should the risk associated with the introduction of biological control agents be estimated?


Earl D. McCoy. Tel: +1 813 974 5219;
fax: +1 813 974 3263; e-mail:


  • 1Florida has an exceptional burden of invasive species. The history of the classical biological control of invasive arthropod pest species in the region largely is one of inadequate pre-release testing for nontarget effects.
  • 2A recent analysis indicated that a substantial risk of nontarget effects may exist in Florida, although the risk appears to be confined to a relatively small group of species within approximately ten families and documented cases of nontarget effects are rare, despite previous risky practices.
  • 3Great progress has been made recently in creating an organized framework for dealing with the uncertainty accompanying biological control importations in Florida and elsewhere. We suggest some ways in which balancing the risks and associated costs of releasing a biological control agent against the risks and associated costs of not releasing the agent may be improved.
  • 4Ultimately, experts will need to set some level of acceptable risk, and the ‘precautionary principle’ has been advanced to guide this process. As it stands, however, the precautionary principle applied to biological control falls short as a guide because it does not provide a prescription for action.
  • 5Florida case histories clearly illustrate both the complexity and urgency related to developing a prescription for action.