WORKSHOP: QUARANTINE SECURITY FOR TEPHRITID FRUIT FLIES PEST IN CITRUS: PROBIT 9 AND ALTERNATIVE LEVELS OF TREATMENT EFFICACY

Tephritid fruit flies are serious pests of citrus. They cause direct fruit damage through oviposition and larval feeding, and warrant regulatory restriction on the movement of citrus fruits across national and international boundaries. Current quarantine mitigations for fruit flies in citrus include fumigation, high-temperature forced-air, vapor heat, cold, and irradiation treatments. Cold treatment has a multitude of schedules with various combinations of low temperature and treatment duration, depending on species of citrus and the guild of associated fruit fly pests. Current probit 9-based mitigation for fruit flies in citrus includes fumigation, high-temperature forced-air, vapor heat, cold, and irradiation treatments. The probit 9 treatment efficacy (99.9968% desired response, e.g., mortality) is the unofficial obligatory level of treatment efficacy for high risk pests in highly susceptible hosts. For naturally poor hosts, the probit 9 standard may be too rigid and impractical, and treatment efficacy lower than probit 9 may be sufficient to achieve the desired quarantine security. In the alternative treatment efficacy approach, risk may be defined either as the number of survivors or as the probability of a mating pair being present in a shipment, rather than as the effective mortality of the treated infesting individuals. The objective of this workshop is to discuss current and explore alternative methods of achieving commodity quarantine security, with particular emphasis on attaining acceptable efficacy levels other than probit 9 and the possibilities of integrating less than probit 9 treatments in developing systems approaches to mitigate risk of fruit fly pests.