Effects of gamma irradiation on European grape vine moth, Lobesia botrana, Purpe

Late grape vine moth Lobesia botrana (Denis & Schiffermuller), pupae were exposed to gamma radiation dosages ranging from 50 to 200 Gy and effects of gamma irradiation on adult emergence were examined. In addition, moths resulting from male and female pupae exposed to the same radiation dosages (50-200 Gy) were crossed to unirradiated insects of the opposite sex. The effects of gamma radiation on fecundity, fertility and survival of F₁ insects to the adult stage were investigated. Results showed that, while adult emergence was not significantly affected at the examined dosages, fecundity of females, whether irradiated or crossed to irradiated males was negatively affected. The effect, however, was more sever when females were irradiated. Fertility of both males and females also decreased with increasing irradiation dose; percentage fertility decreased from about 88% for the control to 37.6 and zero % for irradiated males and females exposed to 200 Gy, respectively. Furthermore, irradiation reduced survival of the progeny of irradiated insects and at 200 Gy dose, all F1 insects died before reaching the adult stage. This study supports a dose of 200 Gy as a phytosanitary treatment against L. botrana and a generic dose of no more than 400 Gy for pupae of Lepidoptera (author).