Wines & Vines Home
Welcome Guest

Asian Fly Detected in Northwest Vineyards

Grapegrowers look out for spotted-wing drosophila, which attacks ripe winegrapes

by Peter Mitham
spotted-wing drosophila
The spotted-wing drosophila's fearsome saw-toothed ovipositor is what makes it so damaging to grapes and other fruit.

Corvallis, Ore.--Northwest grapegrowers are preparing to fight new invasive pests threatening their vineyards. One of the least understood of these invaders is spotted-wing drosophila (D. suzukii), a species native to Asia that was initially reported in California in 2008.

Grapegrowers in Oregon’s Upper Willamette Valley discovered the insect in Pinot Noir grapes last year, and the fly was also detected in a non-commercial winegrape vineyard south of Abbotsford, British Columbia.
The discoveries on grapes and a variety of field berries and stone fruits have brought together researchers from California, Oregon and Washington state as well as federal and provincial scientists in British Columbia to tackle what could be a significant crop pest.

Unlike D. melanogaster and other, more familiar fruit flies that infest damaged and rotting fruit, D. suzukii attacks ripe fruit. Its hosts of choice are thin-skinned fruits which it attacks not opportunistically, through pre-existing lesions in the fruit, but with the assistance of a saw-like ovipositor that cuts through the skin of the fruit. It deposits its eggs, which frequently go undetected until the fruit collapses in on itself from rot.

Unfortunately, most of the research on the pest to date comes from Japan, leaving researchers scrambling to figure out how the fly may adapt to North America. The climate of the Pacific Northwest may limit it to just four generations per year by some counts, though it’s known to be a prolific parent in Japan with upwards of 13 generations per year.

Vaughn Walton, an entomologist with Oregon State University, said the pest is known to be in winegrape vineyards in Japan, but the cultivars are not ones widely planted in North America. Whether grapes are at significant risk is another question.

More facts needed

“We don’t have any real facts at this stage,” Walton said. “The current status is that we’re aware of it, but I don’t know of many growers that have had any real issues.”

Walton told Wines & Vines that one grower may have had grapes rejected on account of damage from the pest; that’s not been confirmed. There are also reports the fly may have successfully overwintered in some vineyards, but that also requires confirmation.

Still, researchers are not resting easy.

Surveillance is being ramped up across the Northwest this year, with Oregon State University set to launch tools that will track fly counts across the state on a weekly basis. B.C. Ministry of Agriculture and Lands staff will also be monitoring Fraser Valley vineyards to determine if D. suzukii poses a significant threat.

Walton said growers may face problems in years where grapes require extended hangtime. The ripe fruit will be a prime target for the flies, and the longer it’s on the vine, the greater the chance it will attract their attention.
On the other hand, cooler temperatures late in the season may inhibit the flies, which thrive at temperatures between 77º and 86ºF (25-30ºC).

“The flies may not develop that quickly, which in turn means that the berries may not spoil that quickly, either,” Walton said.

Fruit flies aren’t the only pests threatening Oregon’s $68 million grape crop
Researchers are also keeping an eye out for European grapevine moth, which already has some Napa Valley vineyards under quarantine. The fear is it may spread to Oregon vineyards.

The biggest focus of researchers are mealybugs, which are suspected to be playing a role in the spread of grapevine leafroll virus in southern and eastern Oregon.


Currently no comments posted for this article.

Wines & Vines Home
866.453.9701 | 415.453.9700 | Fax: 415.453.2517
65 Mitchell Blvd., Ste. A San Rafael, CA 94903
Wine Industry Metrics
Off-Premise Sales » Month   12 Months  
August 2015 $608 million
$8,178 million
August 2014 $568 million $7,729 million
Direct-to-Consumer Shipments » Month   12 Months  
August 2015 $80 million
$1,908 million
August 2014 $78 million $1,686 million
Winery Job Index » Month   12 Months  
August 2015 261
August 2014 218 224
MORE » Released on 09.15.2015
Direct To Consumer
Wine Shipping Report
Download full report »


Practical Winery & Vineyard Library
Search the PWV archive »

  • October 3-11
    Lake Chelan Crush Festival
  • October 9-12
    Santa Barbara Celebration of Harvest
  • October 13-16
  • November 3-6
  • MORE »

Article: Crowd Funds 10,000 Cultivars »
Thanks for interviewing the academic breeders. They would love to be able to raise $167K...
Reader: New York Viticulture
Article: Nielsen Unpacks Package Design »
Okay, I'll state the obvious (to anyone with CPG experience) - the Wine Biz is...
Reader: Joel Miller
Article: Nielsen Unpacks Package Design »
Very interesting reading. Certainly agree with the more indirect approach of evaluating the extent to...
Reader: Roger Brooks
Article: Experimental Solution to Pierce's Disease »
Congratulations to the team! It is amazing what can be done with biological controls. Keep...
Reader: Bruce Coulthard
Article: The Spiciest Wines You Have Ever Tasted »
There are some wines from New Mexico are infused with pepper flavors. Also, The Wine...
Reader: Guest

2015 Directory/Buyer's Guide
The Wines & Vines Directory and Buyer's Guide
Wines & Vines Magazine
Digital Edition Now Available!
Wines & Vines Digital Edition Now Available
The Wines & Vines Online Marketing System
The Industry Standard winery marketing application
Latest Job Listings
 Monterey/Santa Cruz Sa...
 Monterey/Santa Cruz, CA
Sales and Marketing
 San Diego Sales Manage...
 San Diego, CA
Sales and Marketing
 Office And Warehouse M...
 San Francisco, CA
General Administration and
 Hospitality Specialist...
 Napa, CA
DTC, Tasting Room and Retai
 Marketing Associate
 Napa, CA
Sales and Marketing
 Winery Lab Tech
 Sebastopol, CA
Cellar, Lab and Production
 Division Manager - Sou...
 Major Metro Area Of Florida, FL
Sales and Marketing
 Tasting Room Sales Ass...
 Healdsburg, CA
Sales and Marketing
 Materials Planner
 Napa, CA
General Administration and
 Assistant Tasting Room...
 Santa Barbara, CA
DTC, Tasting Room and Retai
More Job Listings >>
Follow Us On:

Home  |  About Us  |  Editors  |  Subscribe  |  Print Edition  |  Digital Edition

Advertise  |  Site Map  |  Contact Us  |  Privacy Policy
Copyright © 2001-2015 by Wine Communications Group, Inc. All Rights Reserved.
No material may be reproduced without written permission of the Publisher.
Wines&Vines does not assume any responsibility for any unsolicited manuscripts or materials.