Biological Control of Invasive Species: Solution or Pollution?

Biological control of invasive species using co-evolved natural enemies has long been considered a safe, cost effective, and environmentally benign tool for pest management. However, recent work has questioned the extent to which these imported natural enemies have negative impacts on populations of non-target species. The result has been a vociferous debate about the safety and proper role of biological control, often without convincing evidence on either side. The issues are particularly well focused in Hawaii, with its high numbers of both endemics and invasive pest species. We review the data concerning environmental impacts from past biocontrol projects, discuss the patterns and generalizations that emerge from retrospective analyses, and consider some new techniques for risk assessment. We then emphasize the need for a federal regulatory framework that is rational, efficient, transparent, and ecologically meaningful.