EFFECTIVENESS AND PERSISTENCE OF THE GRANULOSIS VIRUS OF THE CODLING MOTH CYDIA POMONELLA (L.) (LEPIDOPTERA: OLETHREUTIDAE) ON APPLE

Application of granulosis virus (CPGV) to plots of apple trees reduced deep-entry damage to apples by the codling moth, Cydia pomonella (L.), compared with nontreated apples. However, shallow-entry damage to apples by codling moth was as great, or greater, in virus-treated plots than in nontreated plots. Protection was improved by applying CPGV at least three times during each of the two annual generations of the codling moth compared with less frequent application.Bioassays showed that activity of deposits of CPGV on apples in the field was reduced to approximately 50% of original activity within 2 days after application and to 17% by the 10th day.