Biological control in theory and practice.

Abstract

A stable pest equilibrium is neither a necessary nor a sufficient condition for control: satisfactory control in model systems is compatible with both local extinction of the pest and polyphagy in the natural enemy. Only one of 9 real examples of successful control is convincingly a stable interaction; the remainder show either strong evidence for instability and local extinction of the pest or are consistent with this interpretation. Two strategies by which a natural enemy may control a pest in a nonequilibrium state, termed here 'lying-in-wait' and 'search-and-destroy,' are distinguished.-from Authors