Technical Abstract: Bactrocera latifrons (Hendel) (Diptera; Tephritidae) is a quarantine pest of several solanaceous crops and tropical fruits that are treated using irradiation prior to export from Hawaii to the U.S. mainland. A dose of 150 Gy is approved as a generic irradiation treatment for tephritid fruit flies, but no confirmation of efficacy has been reported for B. latifrons. Dose response of B. latifrons was used to determine the most tolerant life stage and identify a dose that prevents adult emergence. Data indicates doses (plus 95% confidence limits) required to prevent adult emergence of 13.4 (10.0 – 29.6), 17.5 (14.4 – 24.8), and 88.1 (68.0 – 133.8) Gy for eggs, first instars and third instars, respectively. In large-scale confirmatory tests of the most radio-tolerant life stage, a radiation dose of 150 Gy applied to B. latifrons late third instars in bell peppers resulted in no survival to the adult stage of 157,112 individuals, a treatment efficacy consistent with probit 9-level mortality. The relative radiotolerance of Bactrocera cucurbitae and Bactrocera latifrons was also tested. When treated with a diagnostic radiation dose of 30 Gy as third instars in diet, a mean of 6.9% of irradiated B. cucurbitae larvae developed to the adult stage whereas no B. latifrons larvae developed to adults. This report supports the use of a generic radiation dose of 150 Gy in quarantine scenarios to control tephritid fruit flies on fresh commodities.