Assessing and Improving the Safety of Introductions for Biological Control

Abstract

Introduced natural enemies may have direct and indirect effects on non-target species. Methods for evaluating impacts on non-target species are available from literature on evaluating effects on target species, although these are most apt for measuring direct impacts. Despite the availability of methods, there are essentially no solid data concerning impacts on non-target species of arthropods introduced for biological control, even though there is a long history of concerns and current controversy about the risk of such impacts. Lack of evidence concerning nontarget impacts reflects in part lack of research, but it also suggests that nontarget impacts of biological control are much less than from other human activities. More effective quarantine of unwanted species, better screening of intentional introductions of horticultural species, and improved alternative pest management strategies should reduce the need for introductions. Improved efficacy for each introduction should reduce the number of introductions needed. Improved screening of host, habitat, phenology and climate ranges, together with better understanding of their evolution and more information on dynamics of non-target species, should reduce risk per introduction. Critics and practitioners of biological control introductions should work together to generate the knowledge needed for analysis of the risks and benefits.