A series of experiments have been carried out to establish the optimum dosage required for the radiosterilization of adults of Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae) to be used for the sterile insect technique. Experimental data have shown that females are more radiosensitive than males at the 50-60 Gy dose range. In fact, full female sterility has been achieved with the dose of 50 ± 5% Gy. Males, treated with this dose, preserved <1% of the capacity to fertilize eggs. They became completely sterile at 60 ± 5% Gy. High levels of mortality (up to 35%) have been found in eggs laid by females mated with irradiated males. This shows that all irradiated males preserved a remarkable sperm transfer capacity and competitiveness resulting in egg fertilization but not in embryo development. The treatment with the 2 tested doses did not affect insect longevity under laboratory conditions. Considerations regarding the choice of the most appropriate radiosterilizing dose for the autocidal technique are discussed.

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