Spotted Wing Drosophila - what is it and should I care?

Friday, July 27, 2012

Hi Folks,

Thanks to everyone who showed up at Rines Creek last night for our vineyard walk - we had a great turnout on a great night!  A very special thank you to our hosts - John and Colleen Eikelenboom!  :-) 

I am sure most of you have heard of Spotted Wing Drosophila (SWD) - it is a relatively 'new' pest of fruit that was first detected in Ontario in 2010.  It is an invasive vinegar fly of asian of origin that has the potential to cause damage in many fruit crops.  Unlike most vinegar flies that prefer over ripe, damaged or dropped fruit, the SWD female has a serrated ovipositor that allows her to saw through intact fruit and lay her eggs just below the skin.  The larvae then hatch, feed and render the fruit unmarketable.  This oviposition hole can also be a pathway for diseases to enter the fruit causing even further damage. 

Last year, although detected in NS, they never reached damaging levels in any of the fruit crops, however with the early spring and hot summer we've been having, there is concern that they could arrive in the province earlier than last year.  There have been a number of products registered on an emergency use basis for grapes and we have compiled all of that information on our website in a special SWD Pest Management Guide.
There is an ongoing trapping program in a number of different fruit crops in the province and when/if we start to see presence of this pest in Nova Scotia we will be posting updates on all of the fruit blogs to let you know if we think populations are reaching potential pest levels. 

Finally if you are interested in monitoring your own vineyards, Omafra has a great factsheet on monitoring and it gives advice on where to buy or how to easily make your own traps.  Click here to see the factsheet!  If you are doing your own monitoring - make sure you have a pretty good idea of what the adult flies look like (there are some great pictures in the factsheet) as those traps will attract many other species of fruit flies that do not affect grapes so it's important to know the difference!   And as always, if you have questions or concerns, please give us a call! 

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