Adult emergence and F1 generation egg and larval production after γ-irradiation of late pupae of Grapholita molesta (Lepidoptera: Tortricidae)

Abstract

The late pupal stage (pharate adult) of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) close to adult emergence was irradiated with doses up to 350 Gy to determine a dose that could serve as a phytosanitary treatment against Lepidoptera that may pupate in shipped commodities. Adult emergence was not significantly reduced below that of the non-irradiated control until the dose reached 200 Gy. Not until the dose had been increased to 150 Gy was the number of eggs laid significantly less than the control, and oviposition was completely prevented at ≥ 300 Gy. Egg hatch was not significantly reduced compared with the non-irradiated control until the dose reached 150 Gy, and no eggs hatched at ≥ 250 Gy. This study supports a generic radiation dose for pupae of Lepidoptera of at least 250 Gy.