Sterilized by radiation sounds much more risky to me. You don't know what else was changed by the radiation. With gene editing at least you know what you changed.
How would you check millions of insects for actually being sterile? Considering it cost 100M$, I assume they established a non-lethal dose of radiation and then just blasted the insects. Could easily be that one develops beneficial mutations.
Not to sound condescending but I think we have yet to observe radiation leading to useful mutation. Radiation does not lead to 'mutation' in the sense of what you are implying. Rather it leads to DNA damages (breakage of chemical bonds) which usually leads to cancer.
You are definitely right, but I probably should have specified. Irradiating seeds is vastly different than irradiating already living specimen, and hardly transferable to insects I believe.
Irradiating the entire specimen is not so different if you also irradiate the part of them that produces the seed. You're just irradiating an earlier stage of reproduction, the result is unlikely to be different. Seeds have the advantage that they do not move and contain little water that could interfere with the radiation. The insect will produce it's own seed once irradiated, infertile or not.
"The practice of plant irradiation has resulted in the development of over 2000 new varieties of plants, most of which are now used in agricultural production"
