WESTERN CHERRY FRUIT FLY AND ITS MANAGEMENT IN THE PACIFIC NORTHWEST UNITED STATES

Western cherry fruit fly is native to North America, and has been found in the Pacific Northwest states since the 1940s. This pest lives only on cherry, with a single generation per season. It may emerge from the soil over an eight week period, with peak emergence occurring about the time of harvest. Though they are found rarely in commercial orchards, cherry fruit fly is the primary insect pest of importance for sweet cherries in the region. Quarantine agreements between the region and other states or countries result in a zero tolerance for cherry fruit fly larvae in fresh-packed fruit. This zero tolerance has forced growers into intensive programs to achieve perfect control. The advent of the federal Food Quality Protection Act (FQPA) has caused special concern to sweet cherry growers, as the two products used most commonly to control this insect, azinphos-methyl and carbaryl, are receiving special regulatory attention during the evaluation process, due to their very common usage on high-profile crops. It is likely that adjustments in the pre-harvest interval would greatly restrict the usefulness of these products for pest control in sweet cherries, as the target pest is most present near the harvest period. Alternative, effective, and environmentally acceptable cherry fruit fly control materials and methods are being researched and adopted.