Invasion biology: Rethinking our response to alien species

Invasion biology is the study of the reproduction, dispersal and ecological impact of organisms that occur outside of their native range, including exotic pests and biological control agents. Alien species cost California agriculture billions of dollars annually in control measures and crop damage. Societal trends toward increased travel and import of plant and animal products suggest that exotic species will continue to enter California. Understanding the principles of the invasion process will help to predict which species will invade, where invaders will become established, and the effects of invasions on agricultural, urban and natural environments. Improved understanding of the invasion process should contribute to public policies designed to prevent or contain invasions, especially of potential pests that are not yet in the state and whose biology is poorly described.