Spotted Wing Drosophila Found In Grapes
Ξ September 21st, 2009 | → 0 Comments | ∇ Uncategorized |
10/12 Please see this urgent update.
9/22 Correction I wrote to Terry Witt, Executive Director, of Oregonians For Food and Shelter, the organization that appears to have been the original source for the ‘confirmation’ of Spotted Wing Drosophila in Oregon grapes. I asked him for an elaboration of the results of the meeting held earlier today. He wrote,
“We just had the meeting where ODA, APHIS and OSU were present to discuss what is know about the Drosophila suzukii. It appears that the “news” about it being confirmed in Oregon grapes may have come from our email alert about the meeting and at this time has NOT been verified, but growers have just now begun looking at all fruit across the state.’
I further contacted Helmuth Rogg, Entomologist, IPPM Program Manager, Plant Division, of the Oregon Department of Agriculture (ODA). And he wrote,
“Dear Ken,
Yes indeed, today we held an informational meeting on the SWD which was attended by industry, OSU, USDA and USDA-ARS.
And no, we have not recorded SWD in grapes!!!
There is no official record of SWD from grapes. So far we collected SWD from blackberries, blueberries, raspberries, and peaches. We collected SWD from about 6 counties, mainly in the Willamette Valley, of Oregon.
We will prepare a public website on which all interested parties can contribute and receive information. The main objective of this website will be to present information, data and results of work done by ODA, OSU and USDA-ARS. As soon as we have it ready to go live, I will let you know.
We have more information on our Oregon Dept of Agriculture (ODA) website with links to ODA and OSU’s pest alert.”
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The information about outbreaks in Japan, however,still stands. Read the balance of this post and also see THIS LINK.
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The news we have dreaded to hear has been confirmed. The Spotted Wing Drosophila, America’s latest invasive pest, has been found infesting grapes in Oregon. From the Oregon Natural Resources Report:
The spotted wing Drosophila (often named “Dragon Fruit Fly”) has invaded Oregon from California and has already been confirmed in several Oregon fruit crops – blueberries, caneberries and grapes. Stuart Olson, a local peach, apple and cherry grower, believes this could literally shut down fresh fruit sales from Oregon. Unlike the vinegar fruit fly that takes to rotted fruit, this critter infects ripening fruit and is visible in the fruit as a small maggot.
A meeting to discuss the matter has been set for September 22nd. (Follow the ONR link above.)
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According to Martin Damus, Entomologist for the Canadian Food Inspection Agency,
“I contacted officials of our National Plant Protection Organisation that work in Japan, to clarify some questions about the spotted wing drosophila’s hosts, primarily the reports on grapes and apples. Our official there just had to look at Japanese websites (which I cannot do) and found that spotted wing drosophila is classed as an agricultural pest in nearly every prefecture of Japan, and that it has recently been in “outbreak” conditions in blueberries in Aomori prefecture (the northernmost prefecture of the main island, Honshu) and also in outbreak conditions on grapes on Hokkaido (the island north of Honshu, with a very cool-temperate climate).
What no-one has yet told me is if grapes are a “preferred host”, or if they only go to them under outbreak conditions, that is when all preferred hosts are already attacked. I also have no specific information of under what conditions grapes are attacked — are the grapes sound or damaged? Are they ripe? Are they over-ripe? These are questions I still hope to have answers to.
Unfortunately though there is at least evidence that this fly does attack grapes, and that it does so in a cool climate.
Sorry not to be of more help. It would certainly be prudent, I would suggest, of vintners to hang out a few traps and see if they have the fly. The traps are not pheromone lures, so they don’t have to worry about drawing the fly in from other crops. It will only be found if it is already in the wine crop.”
—-9/22 Update. I’ve just received a second email from Martin Damus, Entomologist from the Canadian Food Inspection Agency. He provided THIS LINK to a Japanese website with relevant info on the SWD.
He also adds,
“The webpage also indicates that there are no chemicals registered in Japan for this pest on grapes. This could mean two things: either they haven’t any (not so good), or it is a sufficiently rare occurrence that none are regularly needed (better news). Not sure which is true, if either.”
For further info please see my summation of a presentation given August 26th by UCCE Farm Adviser Mark Bolda and Martin Hauser of the California Dept. of Food and Ag. Spotted Wing Drosophila Emergency Meeting Results
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