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A single male SWD was caught in a trap set on the edge of a blueberry planting in the eastern part of Schuyler County. Traps were checked on May 21, after the cold spell broke and warmer weather prevailed at week's end in the Finger Lakes region. The plants are at early pink bud and progressing to bloom, possibly quickly given the switch to hot weather.

It will be interesting to see if SWD is caught at this site next week. Four traps are set in these blueberries, with two on the row next to a woods in which a small stream gently rolls along the west edge of the planting. Perhaps perfect wintering grounds for our enemy, SWD?

Its too early to spray since there's no fruit. The Quick Guides to SWD Insecticides are not up-to-date yet, but soon will be. In the meantime, consider all the things we can do to thwart this insect that will enhance the efficacy of the insecticide management program:

  • Mowing
  • Weed management
  • Pruning
  • Sanitation
  • Cold storage

Details for SWD IPM in blueberry can be found on this blog, Managing SWD in Blueberries at https://blogs.cornell.edu/swd1/2019/08/02/managing-swd-in-blueberries/. Comprehensive information on SWD IPM is available in Spotted Wing Drosophila IPM in Blueberries from the NE IPM Center SWD Working Group, neipmc.org/go/swdpub2

Picture of three SWD males.
Three male spotted wing Drosophila. Note the spot on each wing, which is on the end of the first vein from the outer edge of the wing.

Like do-it-yourself projects?

Blueberry growers in New Jersey have had success monitoring SWD using sticky cards, baited with a Scentry lure hanging from the bottom edge of the sticky card. Check cards daily for the distinctive males with the spot on each wing. (Don't even bother looking for the females, that's for those of us who enjoy going blind peering through a microscope.)

The 2020 SWD monitoring season is getting underway. We can only hope that the lousy spring weather, frost and freeze events, and delayed plant development have taken their toll on SWD, as well. (Are anyone's fingers crossed like mine?) So far, zero SWD has been caught in traps already set out.

We're using a new system, agpestmonitor, to report trap catch and the NY distribution map won't be on EDDMapS anymore; so change your links. We've got the map on the Cornell Fruit Resources SWD Distribution page, fruit.cornell.edu/spottedwing/distribution/ and on the NYS IPM SWD page, nysipm.cornell.edu/agricultural-ipm/fruits/pest-alerts-fruits/spotted-wing-drosophila/.

This picture of the NY County map checks off those counties where SWD monitoring is taking place in 2020.
The counties checked will have traps set for SWD in 2020. Counties colored gray have zero catch as of May 21, 2020.

Please join me in a round of appreciation for our team of Cornell scientists:

  • Andy Galimberti, Eastern NY Commercial Hort Program
  • Ariel Kirk, Steuben County CCE
  • Barb Neal, Tioga County CCE
  • Dave Thorp, Livingston County CCE
  • Don Gasiewicz, Wyoming County CCE
  • Elisabeth Hodgdon, Eastern NY Commercial Hort Program
  • Faruque Zaman, Suffolk County CCE
  • Grace Marshall, NYS IPM Program
  • Janet van Zoeren, Lake Ontario Fruit Program
  • Jim O'Connell, Ulster County CCE
  • Juliet Carroll, NYS IPM Program
  • Laura McDermott, Eastern NY Commercial Hort Program
  • Liz Tee, Lake Ontario Fruit Program
  • Lydia Brown, Hudson Valley Research Laboratory
  • Natasha Field, Eastern NY Commercial Hort Program
  • Peter Jentsch, Hudson Valley Research Laboratory
  • Sarah Tobin, Eastern NY Commercial Hort Program
  • Sharon Bachman, Erie County CCE

Among us all, we'll have 121 traps set in 23 New York State counties: Albany, Cayuga, Clinton, Columbia, Dutchess, Erie, Essex, Herkimer, Livingston, Niagara, Onondaga, Orange, Orleans, Rensselaer, Saratoga, Schuyler, Steuben, Suffolk, Tioga, Ulster, Washington, Wayne, and Wyoming. Traps are set mostly in blueberry and raspberry, one vineyard site in Suffolk County, and a few sweet cherry orchards in Eastern NY.

Janet van Zoeren and Liz Tee have joined forces with Grace Marshall and me on our tart cherry SWD research along Lake Ontario. These trap catch numbers don't go into the distribution map. But so far, zero SWD caught in tart cherry in the Lake Ontario region, too. Last year we were already catching SWD in tart cherry orchards by this date, so it's looking to be a slow start to SWD arrival.

We're using the Scentry traps and lures again this year. If you want to make your own traps, consult our write up on the fermenting whole wheat dough trap or plan on testing fruit with salt flotation as harvest times arrive. And speaking of harvests— I hope you all come through the spring frost and freeze events with a good crop and have a successful harvest this year!

Stay healthy, wash your hands, and meet online!

Sustained SWD catch was obtained over the last couple of weeks in several counties — Dutchess 1 SWD, Herkimer 6 SWD, Livingston 18 SWD, Onondaga 16 SWD, Orleans at two farms 11 and 9 SWD, and Tioga 1 SWD. Last month, I missed reporting sustained catch in Erie County on June 6, 1 female SWD. Blueberries, raspberries, cherries, gooseberries, currants and many other fruits are being harvested and many will continue with harvests extending over the next several weeks.

Risk from SWD infestation will be high from this point forward in the growing season. Monitor your crops for infestation by taking a sample of fruit at each harvest period and doing a salt flotation test on it. Methods described in Guidelines for Checking Fruit for SWD Larvae in the Field by Laura McDermott, available on Cornell Fruit Resources Monitoring SWD page, fruit.cornell.edu/spottedwing/monitoring/.

Symptoms of SWD infestation in raspberry. The fruit receptacle is stained red with leaking juice, druplets are damaged and dimpled, and fruit melts off the receptacle.
Signs of SWD infestation on raspberry. The fruit receptacle is stained red with leaking juice, druplets are damaged and dimpled, and fruit melts off the receptacle.

Look for signs of infestation in fruit in the field -- look for symptoms of leaky fruit; tiny drops of juice on otherwise perfect fruit; red stains on raspberry fruit receptacles that would otherwise be white; flat, sunken, and dull spots or dimples on fruit surfaces; distorted and disintegrating fruit; leaves stained with juice that has leaked from infested fruit.

Protect ripe and ripening fruit crops from infestation with an insecticide program. Choose a material with excellent efficacy against SWD and an appropriate days-to-harvest interval. Download the Quick Reference Guide to SWD Insecticides at

www.hort.cornell.edu/fruit/pdfs/swd/berry-insecticides.pdf for berries

www.hort.cornell.edu/fruit/pdfs/swd/treefruit-grape-insecticides.pdf for stone fruit and grapes

Details about each County's sustained catch:

  • Dutchess: 7/16/2019, 1 female, raspberry – total 1
  • Erie: 6/6/2019, 1 female, blueberry – total 1
  • Herkimer: 7/15/2019, 2 females & 4 males, blueberry – total 6
  • Livingston: 7/25/2019, 7 females & 11 males, tart cherry – total 18
  • Onondaga: 7/16/2019, 7 females & 9 males, blueberry – total 16
  • Orleans: 7/29/2019, 10 females & 1 male, raspberry – total 11
  • Orleans: 7/29/2019, 7 females & 2 male, raspberry – total 9
  • Tioga: 7/17/2019, 1 female & 0 males, blueberry – total 1

The sustained catch in Tioga County of only 1 SWD in the blueberries after the prior week’s catch of 26 underlines the impact of an insecticide program on SWD populations.

Thank you for monitoring SWD in the Counties with sustained catch!

  • Peter Jentsch and Lydia Brown, Hudson Valley Research Laboratory (Dutchess County)
  • Sharon Bachman, CCE of Erie County (Erie County)
  • David Thorp, CCE of Livingston County (Livingston County)
  • Shona Ort and Barb Neal, CCE of Chemung County and CCE of Tioga County (Tioga County)
  • Elizabeth Tee, Lake Ontario Fruit Program (Orleans County)
  • Ryan Parker and Juliet Carroll, CCE NYS IPM Program (Herkimer and Onondaga County)

This wraps up monitoring for this year.

The ability for the SWD population to explode as summer rolls on was demonstrated last week in several counties where I have research projects. Per trap, 5 to 125 SWD were caught in raspberry, blueberry, and tart cherry in mid-July. The totals for the two to four traps set in the orchards and fields were 14 to 250.

Use this summary as a wake up call! For the weeks ending on the date given:
7/11/2019, Schuyler County, blueberry, 4 traps, 22 SWD (11 males and 11 females)
7/11/2019, Schuyler County, raspberry, 4 traps, 108 SWD (64 males and 44 females)
7/22/2019, Herkimer County, blueberry, 4 traps, 30 SWD (12 males and 18 females)
7/22/2019, Wayne County, tart cherry, 2 traps, 14 SWD (1 male and 13 females)
7/22/2019, Wayne County, tart cherry, 2 traps, 24 SWD (4 males and 20 females)
7/22/2019, Wayne County, tart cherry, 2 traps, 57 SWD (9 males and 48 females)
7/22/2019, Wayne County, tart cherry, 2 traps, 85 SWD (19 males and 66 females)
7/22/2019, Wayne County, tart cherry, 2 traps, 250 SWD (60 males and 190 females)
7/23/2019, Wayne County, blueberry, 2 traps, 131 SWD (53 male and 78 females)
7/23/2019, Wayne County, blueberry, 4 traps, 29 SWD (14 male and 15 females)

In eight of the nine sites a spray program was in place to protect fruit. Fruit is ripe and being harvested – and it’s delicious! Fruit isn’t showing signs of infestation, which means insecticide programs can protect fruit from oviposition, even when SWD numbers are high. Download the Quick Reference Guide to SWD Insecticides at

Photo of the three instars of SWD.
The three instars of SWD will emerge from fruit immersed in a salt solution. The smallest instar is about 0.5 mm long, the largest about 2 mm long.

Salt flotation – What  these numbers also demonstrate is that trap catch numbers aren’t necessarily an indication of whether or not an insecticide program is working. A better indication is to sample fruit and run a salt flotation test. Two berry growers described their success last year using salt flotation to monitor infestations in blueberries, detailed on the blog, Use salt flotation to check for SWD.  A simple method is described in Guidelines for Checking Fruit for SWD Larvae in the Field by Laura McDermott, which can be downloaded from Cornell Fruit Resources SWD Monitoring pages, fruit.cornell.edu/spottedwing/monitoring/. Large scale berry growers will routinely run salt flotation at each harvest, because blueberries, raspberries, and blackberries ripen and are harvested over several weeks. For crops that are harvested all at once, like tart cherry, salt flotation may not be as useful.

Refrigeration – The high populations of SWD, coupled with later ripening of many crops this year, make it even more important to immediately cool fruit after harvest. Cold storage temperatures close to 32°F can greatly inhibit and even kill SWD in fruit. Raspberries, blackberries, blueberries, and tart cherries will all tolerate cold storage temperatures between 32°F to 34°F.

Diversified fruit farms – Protect your crops from SWD, if you’re growing susceptible fruit – June strawberries, day-neutral strawberries, sweet cherries, tart cherries, raspberries, blackberries, elderberries, blueberries, peaches, nectarines, plums, prunes, and thin-skinned grapes. If you have a diversified fruit farm, SWD can spill over from one crop to the next as they are harvested and especially when cull fruit remains in the field. Renovate strawberry fields promptly.

Photograph of high tunnel raspberries.
High tunnel raspberries.

Fruit becomes susceptible to SWD oviposition when it is ripening and is highly susceptible when it is ripe – raspberry, blackberry, blueberry, sweet cherry, tart cherry, elderberry. Fruit that is less susceptible will be attacked when it is at peak ripeness – peach, nectarine, plum, prune, strawberry, grapes. All fruit can serve as a resource for feeding and breeding when it is left for cull in the field. The good news is that, in degraded fruit, SWD doesn't compete all that well with other Drosophilas, like Drosophila melanogaster, our common vinegar fly, which often shows up in our kitchens in late summer or in the winery during press. SWD prefers nice ripe fruit — like we do!

Sustained SWD catch in Eastern NY — Columbia County 5 SWD, Clinton County 5 SWD, & Orange County 36 SWD — and Wayne County 4 SWD. Berries and cherries are being harvested and will continue ripening over the next several weeks. Risk from SWD infestation will be high from this point forward in the growing season.

Monitor your crops for infestation by sampling fruit at each harvest period and doing a salt flotation test. Methods described in Guidelines for Checking Fruit for SWD Larvae in the Field by Laura McDermott, available on Cornell Fruit Resources SWD pages, fruit.cornell.edu/spottedwing/.

Picture of a raspberry fruit with tiny breathing tube threads where an egg is inserted under the skin.
Tiny threads of the SWD egg breathing tubes indicate where an egg was laid in a raspberry. Two eggs were found in 40 fruits examined.

Pay attention to SWD -- look for symptoms of leaky fruit; flat, sunken, & dull spots or dimples on the fruit surfaces; or distorted & disintegrating fruit. Protect ripe and ripening fruit crops from infestation with an insecticide program.

Details about each County's sustained catch:

  • Orange: 6/14/2019, 23 females & 3 males, raspberry & gooseberrytotal 36
  • Columbia: 7/8/2019, 4 females & 1 male, tart cherry – total 5
  • Clinton: 7/9/2019, 3 females & 2 males, blueberry – total 5
  • Wayne: 7/9/2019, 3 females & 1 male, raspberry – total 4

The sustained catch report in Orange County was a month ago! This report slipped my attention, but it underlines that SWD has been found in many fruit plantings for upwards of a month now.

The sustained catch in Columbia County of only 5 SWD in the tart cherries after the prior week’s catch of 32 underlines the impact of an insecticide program on SWD populations and trap catch.

Refer to the insecticide quick guides online. Choose a material with excellent efficacy against SWD and an appropriate days-to-harvest interval.

SWD Insecticides for Berries, www.hort.cornell.edu/fruit/pdfs/swd/berry-insecticides.pdf

SWD Insecticides for Stone Fruit & Grapes, www.hort.cornell.edu/fruit/pdfs/swd/treefruit-grape-insecticides.pdf

Thank you for monitoring SWD in the Counties with sustained catch!

  • Andy Galimberti, CCE Eastern NY Commercial Horticulture Program (Clinton County)
  • Natasha Field, CCE Eastern NY Commercial Horticulture Program (Columbia County)
  • Nate Mengaziol and Laura McDermott, CCE of Orange County and Eastern NY Commercial Horticulture Program (Orange County)
  • Ryan Parker and Juliet Carroll, CCE NYS IPM Program (Wayne County)

Four SWD, 2 females and 2 males, were caught in traps set in a blueberry planting in Onondaga County on July 10, 2019. Traps were checked by Ryan Parker and Juliet Carroll, NYS IPM Program.

This completes first catch for all locations in the SWD Monitoring Network. We'll continue to report sustained catch and provide updated management information to keep you up-to-date on SWD.

SWD distribution map picture.
SWD distribution map for New York. SWD has been found in all the counties in the network, as of July 10, 2019. Counties in white don't have traps or reports in.

Yikes! After catching nothing last week... First catch had 26 SWD caught in four traps set in a blueberry planting in Tioga County — 15 females and 11 males. These traps are being monitored by Barb Neal, CCE of Tioga County and Shona Ort, CCE of Chemung County.

I'd say it's time to protect the crop at this location! We want to bring in a good crop and protect it. For comprehensive information on protecting blueberries from SWD, download and read the new IPM guide from the SWD IPM Working Group.

Spotted Wing Drosophila IPM in Blueberries
neipmc.org/go/swdpub2

Also, refer to the insecticide quick guide to augment the information in the above IPM guide.

A picture showing two male SWD on a blueberry.
Two male SWD on a blueberry, photographed in early September 2013. SWD populations typically build to very high levels in late summer and early autumn.

A single female SWD was caught in a blueberry planting in Orleans County, in traps checked on July 9, 2019 by Liz Tee, Lake Ontario Fruit Program of CCE. While the number is low, it is likely that the SWD catch will be greater next week, but possibly not.

This picture shows the SWD females ovipositor which can slice the skin of ripening fruit and gently place an egg within.
Detail of the spotted wing Drosophila female's abdomen showing the extended ovipositor and the dark, saw-toothed edge used to cut into fruit to lay her eggs inside.

That's one of the things that makes this insect so unnerving — it can explode when you least expect it.

Make sure you keep an eye on how ripe your crop is. No-choice lab tests proved SWD females can lay eggs in blueberries that are pink.

Take the time to carefully plan out your management strategy now. Review resources available online to help you learn how to protect ripe and ripening fruit crops from infestation.

First catch was obtained on July 8, 2019 in Herkimer County. Nine SWD — 3 females and 6 males, distributed both within and on the edge of the planting. Numbers of SWD being caught are starting to escalate.

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

It's time to get an insecticide program geared up for ripening and ripe fruit. This season will be demanding and all tactics should be brought to bear on SWD to keep it in check!

Refer to the quick reference guides for:

Other tactics that can help are:

  1. Sanitation – pick off and remove all cull fruit from the planting.
  2. Mowing – keep the environment hot, sunny, and dry.
  3. Weed management – keep the environment hot, sunny and dry, and provide no alternate hosts.
  4. Pruning – keep the environment hot, sunny, and dry, and improve spray penetration and deposition.
  5. Cold storage – immediately after harvest, place harvested fruit into a cooler at 32°-34° F and hold it there, to kill larvae and eggs, until sold.

One female SWD was caught in two traps placed in a small raspberry patch in Livingston County. Traps were checked on July 3, 2019 by Dave Thorp, CCE Association of Livingston County.

Only four counties in the network, two added just last month, have not yet caught SWD — Herkimer, Onondaga, Orleans, and Tioga. All these counties have traps set in blueberry fields. In Orleans a second site has traps set in raspberry.

Picture of a Scentry trap for monitoring SWD that is set in a raspberry planting.
Scentry trap for SWD set in a raspberry patch.

Fruit that is ripe is at risk of infestation. Consult Cornell Fruit Resources SWD Management, fruit.cornell.edu/spottedwing/management/.

More information on SWD is online:

Review the Quick Guide to SWD Insecticides at

www.hort.cornell.edu/fruit/pdfs/swd/berry-insecticides.pdf for berries

www.hort.cornell.edu/fruit/pdfs/swd/berry-insecticides.pdf for stone fruit and grapes

 

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