This new pest of soft fruits arrived in Cawston and Keremeos in 2010. In the Similkameen valley Spotted Wing Drosophila was found in cherries, nectarines, backyard berry patches and mulberries. They may have present but unreported in other crops. One million pounds of Okanagan cherries were found unfit for market last year and shipments of cherries destined for international markets were denied phytosanitary certification due to spotted wing drosophila.
To date the numbers of this pest are lower than 2010, possibly in part due to cooler temperatures slowing down its life cycle. To keep numbers down and minimize economic losses to Spotted Wing Drosophila it is absolutely necessary for everyone-whether you have a back yard raspberry patch or 10 acres of cherries-to do their part.
Commercial growers: All soft fruit are vulnerable to Spotted Wing Drosophila and you should do what you can to protect your crops. Four products are registered for use; Entrust, Delegate, Malathion 85 E and Ripcord 400 EC. Information on monitoring and management including spray guidelines for these products is available at http://www.agf.gov.bc.ca/cropprot/swd.pdf. Moving your fruit into cold storage for at least 24 to 48 hours might be a good idea. Preliminary research indicates this may be sufficient to kill eggs and larvae in fruit. More research on this is underway.
Everyone: Strip your trees and berries clean. Culled berries and fruit may harbor Spotted Wing Drosophila. Flies may emerge from culls left in an orchard or garden and move on to neighboring ripening fruit. Bury culls at least 12 inches deep or sort culls into plastic bags and let them sit in the sun for a few days, the heat will likely kill them. Research on this is also currently in progress.
Questions? Call Tamara Richardson (250) 502-7546.
Contributed by Tamara Richardson and Linda Edwards