PERSPECTIVE ON THE USE OF EXOTIC NATURAL ENEMIES FOR BIOLOGICAL-CONTROL OF PEST GRASSHOPPERS (ORTHOPTERA, ACRIDIDAE)

A previous manuscript (Lockwood 1993) questioned the introduction of exotic natural enemies for control of grasshoppers that affect rangeland and agricultural crops. This article presents some opposite viewpoints on the use of classical biological control, grasshopper biology, economic impact, management tactics, the specific natural enemies either released or slated for release, environmental concerns, and the review of these programs before release. In many areas, full agreement is indicated with positions presented by Lockwood; however, major differences of opinion exist. We believe that there is no scientific basis for establishing the new terminology ''neoclassical biological control,'' so traditional terminology is retained. Data on the use of arthropods and pathogens in classical biological control (including use of exotic natural enemies for control of native pests) show that this approach to pest management has controlled important pest species, has been associated with few if any serious environmental problems, and is a viable technique that was endorsed by the National Academy of Sciences and others. Therefore, the notion that the introduction of exotic natural enemies is categorically inappropriate is not accepted, nor is the idea that increased federal regulation would necessarily improve natural enemy establishment, improve control success, or eliminate negative environmental side effects. Rather, it is felt that mandatory Environmental Assessments and Environmental Impact Statements would restrict implementation of classical biological control. The specific programs questioned by Lockwood (1993) were based on significant biological information, were reviewed thoroughly, and hold potential to provide long-term mitigation of a severe economic pest problem while reducing environmental risk linked with widespread pesticide application.