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2018 SWD distribution map, showing counties where traps were being monitored.

As of August 9, 2018, all 35 SWD trapping sites have sustained catch of SWD in the 23 counties in New York where monitoring was taking place. First trap catch across the New York State network spanned 72 days, from May 22 (Erie County) to August 2 (Herkimer County). All sites used the Scentry trap and lure.

This year brought fewer reports of severe infestations to my attention, than in 2017. It may have been the hot weather, the hot winds, the cold nights in spring, the drought. Although we saw early arrival of SWD in 2018, there wasn't the rapid, consistent build-up nor the early sustained catch as seen in 2017.

High pressure from SWD always builds in late summer. Those of us continuing to monitor SWD in berries are catching 100-200 SWD per trap in the week ending August 28. SWD is likely distributed across the state and soft, late-season fruits, such as fall raspberry, late blueberry varieties, plums, peaches, and pears may be at risk of infestation. To prevent fruit infestation now, if fruit is to remain hanging for weeks to come, susceptible fruit should be protected with an insecticide program.

Protect crops from SWD- (SWD hosts)

  • late-summer-ripening raspberry, blueberry, blackberry, elderberry
  • monitor for infestation in less susceptible fruits: ever-bearing strawberries, thin-skinned grapes, peaches, plums and prunes with salt flotation

Management tactics- (SWD management)

  • timely insecticide sprays (berries) (tree fruit and grapes)
  • rotate active ingredients—read and follow insecticide label directions.
  • weed management
  • canopy management
  • clean picking
  • remove or spray dropped fruit

Find out more about SWD on the Cornell Fruit Resources SWD pages.

Please join me in thanking those who contributed time and effort to the 2018 SWD trap network!

  • Amy Ivy, CCE Eastern NY Horticulture Program (Clinton and Essex County traps)
  • Bernie Armata, CCE Association of Herkimer County (Herkimer County traps)
  • Dave Thorp, CCE Association of Livingston County (Livingston County traps)
  • Don Gasiewicz, CCE Association of Wyoming County (Wyoming County traps)
  • Faruque Zaman, CCE Association of Suffolk County (Suffolk County traps)
  • Jim O’Connell, CCE Association of Ulster County (Ulster County traps)
  • Juliet CarrollNicole Mattoon and Ryan Parker, CCE NYS IPM Program (Cayuga, Onondaga, Schuyler and Wayne County traps)
  • Laura McDermott and Natasha Field, CCE Eastern NY Horticulture Program (Albany, Columbia, Rensselaer, Saratoga, Schenectady and Washington County traps)
  • Peter Jentsch and Zayd Normand, Hudson Valley Laboratory (Dutchess and Ulster County traps)
  • Sharon Bachman, CCE Association of Erie County (Erie County traps)
  • Shona Ort, CCE Association of Chemung County (Chemung County traps)
  • Tess Grasswitz, CCE Lake Ontario Fruit Program (Niagara and Orleans traps)

As expected this late into the summer season, SWD was caught a second week in a row at a blueberry farm in Herkimer County.  7 males were caught in the traps set in and around the blueberry field, during the week ending August 9, 2018. These traps are being monitored by Bernie Armata, Herkimer County Cornell Cooperative Extension.

Checking fruit for larva with salt flotation at a workshop on SWD sponsored by the NYS Berry Growers Association.

The grower has continued monitoring for fruit infestation using salt flotation. Harvest is winding down and the farm will be closing in a few days.

If you need more information about SWD, consult the web pages listed below on Cornell Fruit Resources, www.fruit.cornell.edu, under Berry Integrated Pest Management, New and Emerging Pest Issues in Berries:

  • SWD monitoring, fruit.cornell.edu/spottedwing/monitoring/ – describes what you can do.
  • SWD management, fruit.cornell.edu/spottedwing/management/ – describes what you should do.
  • SWD distribution, fruit.cornell.edu/spottedwing/distribution/ – describes where the CCE network is finding it.

Blueberry harvest is underway at a farm in Herkimer County and SWD hadn't been found. But that changed as of Thursday! Two male SWD were caught, one in each of two traps set within the planting, during the week ending Thursday, August 2, 2018. Two traps set on the edge of the planting caught zero SWD.

Only one County in Cornell's SWD Network hasn't caught SWD. SWD populations continue to build through summer and into fall, placing fruit at extreme risk.

This grower will collect a fruit sample now and test it via salt flotation to see if there is an infestation. You can do this, too! Now is the time to be checking your fruit, because SWD has been found at all but one location in the New York State SWD Network. Monitor for SWD. Protect ripe and ripening fruit crops from infestation.

Herkimer County traps are being monitored by Bernie Armata, Herkimer County Cornell Cooperative Extension.

Both sites in Chemung County are now at sustained catch. During the week ending July 27, 2018, 4 males were caught at one site with a raspberry and a blueberry planting, and 6 males and 2 females were caught at the other site in a blueberry planting. These sites are being monitored by Shona Ort, Chemung County Cornell Cooperative Extension.

Insecticide programs are in place now, which will suppress SWD population growth within the planting. In unmanaged locations, SWD numbers will continue increasing as approximately 10 generations of the insect develop during summer and early fall. A recap:

  • SWD monitoring, fruit.cornell.edu/spottedwing/monitoring/ – describes what you can do.
  • SWD management, fruit.cornell.edu/spottedwing/management/ – describes what you should do.
  • SWD distribution, fruit.cornell.edu/spottedwing/distribution/ – describes where the CCE network is finding it.

Remember, the short life cycle and 10+ generations per year will make for high pressure situations in a few weeks’ time. Management, management, management…

Why does the SWD population explode?
You can do the math. Let’s think optimum conditions for SWD development. A single female can lay around 350 eggs during her lifetime, about 15 per day. The egg to adult phase of the life cycle takes as little as 6 days. So, one female in one day can result in 15 more adults 6 days later, and, during those 6 days, she will have laid another 90 eggs. 6 days after that, those 90 eggs will all be adults. Half of the 105 adults will be females, capable of laying ~350 eggs during their lifetimes…that’s 18,375 eggs or 9,187 females in about two weeks.

Meet and greet - male (right) and female (left) SWD - on a raspberry fruit.

A typical life span for SWD is 3 to 9 weeks and there are estimated to be about 10 generations per year in the US, depending on climate. Back to the one female. Let's say that she lays 70 eggs per week and, when she dies in 5 weeks she's laid 350 eggs and, by then, about 280 of those are adults. Half of those adults, 140, are females and, by then, have laid 49,000 eggs, 29,400 of which will, by then, be adults. Half of those adults, 14,700 are females and, by then, have laid 3,087,000 eggs ...I'm lost and I probably made a mistake...but you get the idea - over 3 MILLION in five weeks from ONE (really from two, because you need a male and a female).

After a very early first catch in late May, SWD has again been caught in Erie County. Re-catch occurred the week ending July 12, 2018, when two female SWD were caught, one each in traps on the edge of and within the blueberry planting. Seven SWD were caught the subsequent week, ending July 18, three females in the edge and three females and one male within the planting.

Traps at this location are being monitored by Sharon Bachman, Erie County Cornell Cooperative Extension.

Blueberries are ripe across the region and harvests are underway. Once again, it’s time to pay attention to SWD and protect ripe and ripening fruit crops from infestation.

SWD found in Dutchess County, as of the week ending on July 10, 2018, and sustained catch during the week ending July 17.  On July 10, four females and one male were found in the raspberry crop, and three females and two males were caught in the nearby hedgerow. On July 17, only 1 female was found in the traps set in the crop and one female in the hedgerow.

Female SWD, on left, has large ovipositor. Male SWD, on right, has a spot on each wing.

Interestingly, the number of SWD caught decreased significantly from the first week to the second week possibly indicating that effective management tactics were put into place at this location.

SWD needs to be managed in susceptible fruit — know if it's on your farm and know how to fight it!

The traps in Dutchess County are being monitored by Zayd Normand, summer intern, working with Peter Jentsch, Hudson Valley Research Laboratory.

A blueberry grower in Tioga County monitoring traps daily for male SWD in their planting caught 6 males in one day, July 21, 2018. No SWD were found in traps up to and including Friday, July 20th.

Homemade SWD trap. The red cup contains an apple cider vinegar drowning liquid and a specimen cup with a wheat dough bait. Traps are checked daily for males.

The two traps are set in the hedgerow adjacent to the blueberry field. To quote the grower,

"Spraying is going to be hard with wet weather for the rest of the week."

The blueberry grower is making their own traps, using whole wheat dough as the bait and apple cider vinegar as the drowning liquid. Instructions for these whole wheat dough traps are on the SWD Monitoring page.

Only two Counties reporting zero SWD trap catch (gray) - Herkimer and Orange - as of July 23, 2018.

 

Elsewhere, across the CCE SWD monitoring network, all locations have reported in. Only the sites in Orange County and in Herkimer County have yet to catch SWD. Dutchess and Erie Counties are now at sustained catch. Details of these findings will be reported in a separate blog.

Three SWD were caught in two traps set in and on the edge of a blueberry planting in Chemung County; 2 males and 1 female. These traps are being monitored by Shona Ort, Chemung County Cornell Cooperative Extension.

Blueberries are ripe at this location and an insecticide program will be put into place this week.

Quick Guide to Berry Insecticides for SWD

Two male SWD on a blueberry, in early September 2013. SWD populations typically build to very high levels in late summer.

Although the hot and dry weather has compressed fruit maturity such that early-, mid-, and late-season blueberries are ripening almost simultaneously, this weather will also keep SWD population growth somewhat suppressed. ...but don't count on the weather to protect your fruit. SWD populations will continue to build through early fall until reproductive diapause sets in around October.

Detailed information on spotted wing drosophila is on the Cornell Fruit Resources website at http://fruit.cornell.edu/spottedwing/.

A male spotted wing drosophila (SWD) on blueberry; another likely SWD is in the background.

SWD has now been caught two weeks in a row in Columbia, Livingston, Onondaga, Orleans, Saratoga, Washington, Wayne, and Wyoming Counties. It's time to pay attention to SWD and protect ripe and ripening fruit crops from infestation.

Details about each County's sustained catch:

  • Wyoming: 7/12/2018, 2 females & 2 males, strawberry & blueberry
  • Columbia: 7/16/2018, 4 females & 1 male, sweet & tart cherry
  • Washington: 7/16/2018, 2 females & 1 male, blueberry
  • Orleans: 7/17/2018, 5 females & 3 males, hedgerow by raspberry
  • Wayne: 7/17/2018, 3 females & 3 males, raspberry
  • Livingston: 7/18/2018, 1 female, blueberry
  • Onondaga: 7/18/2018, 1 female, blueberry
  • Saratoga: 7/19/2018, 2 females & 1 male, blackberry

Thank you for monitoring SWD in these Counties!

  • Don Gasiewicz, Wyoming County Cornell Cooperative Extension (CCE)
  • Natasha Field and Laura McDermott, CCE Eastern NY Commercial Horticulture Program (Columbia, Washington, Saratoga Counties)
  • Tess Grasswitz, CCE Lake Ontario Fruit Program (Orleans County)
  • David Thorp, Livingston County CCE
  • Nicole Mattoon, Ryan Parker and Juliet Carroll, CCE NYS IPM Program (Onondaga, Wayne Counties)

One female SWD was caught in a trap set in a small blueberry patch in Livingston County during the week ending July 12, 2018. These traps are being monitored by Dave Thorp, Livingston County CCE, and Ryan Parker, NYS IPM, sorted through the catch to identify the SWD.

A recap:

  • SWD monitoring, fruit.cornell.edu/spottedwing/monitoring/ – describes what you can do.
  • SWD management, fruit.cornell.edu/spottedwing/management/ – describes what you should do.
  • SWD distribution, fruit.cornell.edu/spottedwing/distribution/ – describes where the CCE network is finding it.

Remember, the short life cycle and 10+ generations per year will make for high pressure situations in a few weeks' time. Management, management, management...

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