Strawberry (Fragaria ananassa Duch) is one of the representative fresh agricultural products exported overseas from South Korea. The greenhouse whitefly (Hemiptera: Aleyrodidae), Trialeurodes vaporariorum, is an economically important insect pest of commercial strawberries in South Korea. The objective of the present study was to evaluate the effects of electron beam and X-ray on the development and reproduction of T. vaporariorum. To determine the radiation dose as a quarantine treatment for strawberry, T. vaporariorum were placed at the top, middle, and bottom location in boxes filled with strawberry fruits and irradiated. Eggs were completely inhibited from hatching at 50 Gy, and adult emergence of 3rd nymphs was completely suppressed at 150 Gy in both electron beam and X-ray. Some adults spawning occurred at 100 Gy. However, F1 hatchability was completely suppressed. The results suggest that T. vaporariorum was the most radiotolerant to both of ionization energy at the nymph stage. The dosimetry results showed that the penetrating power of ionizing radiation in boxes filled with strawberry fruits was the lowest at the bottom location. A treatment dose of 150 Gy is adaptable as a quarantine treatment to T. vaporariorum nymph in strawberry fruit. Our results indicate that ionizing radiation could be recommendable as a phytosanitary treatment for quarantine.