SAFETY AND REGISTRATION OF MICROBIAL AGENTS FOR CONTROL OF GRASSHOPPERS AND LOCUSTS

Microbial control agents offer a method of pest control using organism s that are a natural component of the environment and are usually much more selective than chemical pesticides. Furthermore, they can usuall y be integrated with other methods of control, and may provide prolong ed control by establishment within the host population. However, micro bial control agents also possess properties that can pose human and en vironmental risks depending on the nature of the pathogen and its patt ern of use. We present an overview of issues concerning the safety and registration of microbial control agents with emphasis on pathogens o f locusts and grasshoppers. The potential safety issues and other cons equences of concern from the deployment of microorganisms for pest con trol are: (1) pathogenicity to non-target organisms, (2) toxigenicity to non-target organisms, (3) competitive displacement of microorganism s, and (4) allergenicity. Inundative control methods pose unique risks because the pathogens must be produced in large quantities, stored, t ransported, and applied, usually in concentrations much higher than wo uld normally ever occur naturally. The overriding concern in introduci ng an exotic agent is the risk to non-target beneficial organisms, bec ause once the agent becomes established. it will in most situations be impossible to eradicate. However, if indigenous organisms are used, t here is relatively little risk of irreversible, long-term detrimental effects. A synopsis of safety testing results of some of the more prom ising microbial control agents for grasshoppers and locusts and an eva luation of their potential hazards are presented. Safety to vertebrate s is evaluated by a tiered series of laboratory test requirements. Ass essments on hazards to non-target invertebrates are based principally on results of laboratory bioassays. Safety tests should be chosen with regard to the biological characteristics of the agent and should not impose standards that are more stringent than those imposed on other f orms of pest control. Regulatory oversight should assure the integrity of the environment and safety of the public, while at the same time n ot unduly hampering the development, registration, and use of more sus tainable pest control methods.