Technical Abstract: Irradiation was examined as a potential phytosanitary treatment to control white peach scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) (Homoptera: Diaspididae), a serious quarantine pest of papaya in Hawaii. Dose response tests were conducted with 2nd stage nymphs, adult females without eggs, and adult females with eggs at a series of irradiation doses between 60-150 Gy to determine the most tolerant stage. The adult female with eggs was the most tolerant stage. In large-scale validation tests 35,424 adult female scales with and without eggs irradiated at a dose of 150 Gy produced no F1 generation adults with eggs. Irradiation treatment with a minimum absorbed dose of 150 Gy should provide quarantine security for white peach scale on exported papaya and other commodities.