Nontarget Effects of Biological Control: What are We Trying to Miss?

Abstract

The history of pest management in general (Perkins 1982), and biological control in particular (Coppel and Mertins 1977, Caltagirone 1981, Goeden 1988, Van Driesche and Bellows 1996), has been thoroughly analyzed in terms of the dominant practices and how these actions relate to competing philosophies of ecological intervention (e.g., integrated vs. total pest management). While it is evident how environmentalism, as a social phenomenon, has altered the forms and concepts of pest management, it is not so clear how ecology, as a scientific discipline, might change the field of pest management. A great deal of work has been dedicated to the notion of “nontarget” effects, particularly as they relate to chemical control methods, but only recently have we begun to critically assess what exactly constitutes a “nontarget.” From a simple perspective this would seem to be self-evident—all organisms other than the pest are nontargets. However, this tautological approach does little to advance the science of pest management, and it is clear that in practice, the nature of the targets and nontargets is far from simple. The (re)conceptualization of the target can lead to important changes in pest management (e.g., defining the target based on an economic threshold, USDA 1996). Extending these principles to our understanding of nontargets promises to open new avenues for monitoring and protecting those elements that we wish to protect from the hazards of pest management practices in general, and biological control in particular.