Studies were undertaken to determine whether irradiation treatmentat 250 Gy, an accepted treatment for disinfestation of fruit flies inspindaceous fruits from Hawaii, would also disinfest fruit of twospecies of Cryptophlebia. Cryptophlebia illepida (Butler)was determined to be more tolerant of irradiation thanCryptophlebia ombrodelta (Lower); therefore, C.illepida was the focus for detailed tests. Using the criterion ofsuccess in developing to the adult stage, the pattern of tolerance toirradiation in C. illepida was generally eggs < earlyinstars < late instars < pupae. The most tolerant stagepotentially occurring in harvested fruits was late (fourth and fifth)instars. Development to adult was reduced slightly in late instarsreceiving an irradiation dose of 62.5 Gy, whereas development to adultwas dramatically reduced in late instars receiving irradiation doses≥125 Gy. No C. illepida larvae receiving an irradiationdose ≥125 Gy emerged as adults and produced viable eggs, indicatingsterility can be achieved at doses well below 250 Gy. In large scaletests, when 11,256 late instars were irradiated with a target dose of250 Gy, 951 pupated (8.4%) and none eclosed as adults. Within thepupal stage, tolerance increased with age; 7- to 8-d-old pupae (theoldest pupae tested) treated with an irradiation dose of 125 Gyproduced viable offspring, whereas those treated with a dose of 250 Gyproduced no viable offspring. Irradiation of adults with a target doseof 250 Gy before pairing and mating resulted in no viable eggs.Irradiation of actively ovipositing adult females resulted in nosubsequent viable eggs. Therefore, the irradiation quarantine treatmentof a minimum absorbed dose of 250 Gy approved for Hawaii’s fruits willeffectively disinfest fruits of any Cryptophlebia inaddition to fruit flies.