Technical Abstract: Quarantine measures and treatments are applied to exported commodities to control regulatory pests and prevent their introduction into new areas. Nonhost status can be an effective measure used to achieve quarantine security. If it is determined that the regulatory pest will not be introduced with the fruit into the import area, then the nonhost approach can stand alone. The numbers of insects tested during investigation of nonhost status will determine the level of statistical confidence. If the level of confidence of nonhost status is not very high, then it can be part of a systems approach. Certain countries require that either 30,000 or 93,613 tephritid fruit flies be treated experimentally with a quarantine treatment with no survivors to achieve 99.99 or 99.9968% mortality, respectively, at the 95% confidence level to meet quarantine security. This report outlines how the level of confidence in nonhost status can be quantified so that its equivalency to traditional quarantine treatments may be demonstrated.