Spotted wing drosophila adult flies were caught in vinegar fly traps in two cherry orchards in Creston on June 14. This is a serious pest of concern because, if left untreated, it can cause significant economic damage to soft fruit such as cherries, other stone fruit and berries. Female flies lay eggs in ripening fruit and the larvae (maggots) develop in the fruit, making it unmarketable.
Spotted wing drosophila was first detected in the Southern Interior valleys of B.C. in 2009. It was widely distributed in 2010 with high numbers captured in the Okanagan and Similkameen valleys and low numbers in Creston. Significant economic impacts to British Columbia’s cherry industry resulted. In contrast, very low numbers of spotted wing drosophila flies were found in 2011 in the Okanagan and Similkameen valleys and none in Creston, and no economic damage to soft fruit occurred.
As a result of the recent capture of spotted wing drosophila in Creston, soft fruit growers are being reminded to manage the pest, as damage has already been reported in some early cherry varieties in Eastern Washington and California. The flies are being monitored with apple cider vinegar traps and additional traps can be purchased from Growers Supply Co Ltd.
Emergency registration products are available for the control of this pest. Commercial soft fruit growers should check the Ministry of Agriculture and Okanagan-Kootenay Cherry Growers Association websites for weekly monitoring reports and information on how to manage spotted wing drosophila. Commercial growers may also contact Duane Holder for further information on the management of this pest
Everyone’s co-operation is needed to manage and prevent the spread of this serious pest. Abandoned and uncared for trees may harbour the pest and if left untreated may pose a serious threat to neighboring orchards. Leftover and fallen fruit should be cleaned up and properly disposed of by tying up in plastic bags or frozen for 48 hours before disposal. Do not compost infested fruit as home composting will not kill the flies.
Homeowners can monitor spotted wing drosophila with apple cider vinegar traps. A brochure at www.agf.gov.bc.ca has information on making your own traps and how to manage the pest.
—OKANAGAN-KOOTENAY CHERRY GROWERS ASSOCIATION