Procedures and policies in the USA regarding precautions in the introduction of classical biological control agents

Abstract

Classical biological control, the introduction of exotic natural enemies to control non‐indigenous insect pests and weeds, has been practised in the USA for over 100 years. To date, there have been no fully documented, substantial negative results, and many important insect pests and weeds have been successfully controlled. Over the past decade, concern about the safety of biocontrol agents has increased in line with concern for general health of the natural, native biota. This concern has focused primarily on endangered, threatened, and listed species of plants, but is broadening to include most other organisms. Scientists, administrators and others involved in the process have long recognized the need to ensure that natural enemies of weeds do not attack commercially or horticulturally important plants and to ensure that natural enemies of insects do not attack beneficial species. Procedures for testing the host specificity of the natural enemies of weeds in their area of origin, before shipment to the country of release, have been developed to quite high levels of reliability but there is need for further improvements. Further host‐specificity testing is often required in quarantine in the USA. The rigour of this system is helped by the fact that all applications for permission to introduce biocontrol agents are examined by an Inter‐agency Technical Advisory Committee for Biological Control of Weeds (TAGBCW) before import permits are issued by the relevant authority (USDA APHIS/PPQ). TAGBCW review includes study of research plans and of lists of host plants for testing host specificity; it also analyses and offers advice on potential conflicts of interest. A ‘TAGBCW’ could be recommended for the European Union. With regard to natural enemies of insect pests, there is relatively little need for host‐range testing of most parasitoids because these are generally co‐evolved and intimately related organisms that are restricted to one or a few host species. Concern about the potential impact of oligophagous predators on non‐target organisms has increased recently and is a developing field of research. Some operating procedures that involve safety are discussed. The import permit system in the USA is presented, and two suggestions for changes in European permit procedures are suggested. Past regulatory procedures for classical biological control in the USA are described, and the current situation is presented.