ORCHARD TRIALS IN CANADA ON CONTROL OF CYDIA-POMONELLA (LEP, TORTRICIDAE) BY GRANULOSIS-VIRUS

Cydia pomonella (L.), a major pest of apples in Canadian orchards, is susceptible to a granulosis virus (CpGV). Orchard trials with differen t formulations of CpGV in Ontario, where C. pomonella has two generati ons per year, indicated that as many as seven applications of virus wo uld be needed to maintain the percentage of fruit with deep larval ent ries below 4%. In Nova Scotia, where there is only one generation of C . pomonella per year, two applications of CpGV usually were needed alt hough, in some cases, one sufficed. The protection of fruit conferred by CpGV equalled that by the organophosphate insecticides, azinphosmet hyl or phosmet, in some tests. The advantages of a selective treatment , such as CpGV, over use of broad-spectrum insecticides are discussed.