Effects Of Irradiation On Codling Moth (Lepidoptera: Tortricidae) First Through Third Instars In Sweet Cherries

Codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is a serious pest of apple (Malus domestica [Borkh.]), pear (Pyrus communis [L.]), and occasionally, stone fruit (Prunus persica [L.]). Its presence in sweet cherries is rare and presumed to occur in areas where high populations in pome fruits occur near sweet cherries, Prunus avium (L.). Nevertheless, the potential of codling moth residing in a sweet cherry destined for an export market, especially to Asian Pacific countries, has led to the continued use of methyl bromide, an ozone-depleting fumigant, to prevent the accidental spread of this pest. Over the past 20 yr, internationally accepted alternative phytosanitary treatments using ionizing radiation have been developed. This is the first report of an irradiation dose response of codling moth in sweet cherries. We treated the first three instars of codling moth in export-quality sweet cherries and found that the third instar was the most radio-resistant, requiring a dose of approximately 250 Gy to prevent adult emergence. This dose is higher than those reported for fifth-instar codling moth in apples and artificial diet but should not delay any efforts in using this highly effective treatment to meet quarantine restrictions against this pest.