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In a blueberry planting in Herkimer County six SWD were caught in four traps during the week ending June 30, 2020. No zero catch was obtained at this site. Traps were initially set on June 23. These traps are being monitored by the grower at this location.

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

Across New York there is only one location in the SWD Monitoring Network where SWD hasn't been caught yet, in Western, NY. Weather in Western NY has been hot. Temperatures have reached or exceeded 90° F during the past several days. Lack of rain has occurred in many areas.

Over 90° F weather doesn’t favor SWD survival. This was determined in lab assays following 24-hr-long exposure to high temperature treatments and assessing the lethal temperature for 25%, 50% and 75% of the treated SWD. I wrote a blog about this research in 2014, might be worth a look, Frozen or baked SWD?, at blogs.cornell.edu/swd1/2014/04/08/frozen-or-baked-swd/.

I would hazard a guess that the lethal effects of high temperature and an insecticide are enhanced one by the other, possibly synergistically – though this would require further research.

Mowing row middles makes a lot of sense right now – eliminate cool, shady refuges for SWD; reduce competition for water from groundcover.

Learn more about SWD. Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, fruit.cornell.edu/spottedwing/.

In a blueberry planting in Steuben County, we now have first catch. A single male was found in a trap set on the edge of the planting that was checked on July 1, 2020 by Ariel Kirk, Agriculture Educator, Steuben County Cornell Cooperative Extension. A big shout out to Ariel. This is her first year with the network.

In many areas of New York State, blueberries are ripe, but in others, they are still green. Make sure you tailor your SWD Management accordingly, because green and hard fruit aren't susceptible to SWD.

This picture shows a treefrog sitting on the lid of a trap for SWD.
A convenient place for a treefrog to sit to capture a free meal of fruit flies attracted to the SWD trap. It even went along for the ride when the trap was checked!

Some help from a treefrog? Or is the treefrog enjoying easy pickings? I think this is the common gray treefrog (Hyla versicolor). No matter, these insectivores help reduce the number of insects in our fields. This toad helped Grace Marshall, NYS IPM, check an SWD trap this spring when blueberries were in full bloom.

Sustained catch, was obtained in 11 berry plantings in nine counties in NY between June 23 and 29. Trap catch numbers are creeping up and are hitting higher numbers some locations. Harvest continues in June strawberries and is now underway in raspberries (yum, my personal favorite) and blueberries.

With SWD found across most traps in NY and numbers climbing, it will be imperative to begin a spray program to protect fruit. SWD populations built up this year to coincide with berry and cherry harvests. This translates into a challenging year for SWD management.

Sustained catch on June 23

  • Clinton County – 1 male and 1 female in a blueberry planting.
  • Essex County - 6 males and 16 females in a raspberry planting.
  • Orange County - 35 males and 21 females in a raspberry field.

Sustained catch on June 25

  • Saratoga County – 4 males and 10 females in a blackberry planting.
  • Saratoga County – 3 males and 5 females in a tart cherry orchard.
  • Schuyler County - 1 male and 2 females in a blueberry planting.
  • Schuyler County - 1 male and 9 females in a raspberry planting.
  • Cayuga County - 1 males and 2 females in a raspberry planting.

Sustained catch on June 29

  • Columbia County - 2 males and 4 females in a tart cherry orchard.
  • Washington County - 1 male and 7 females in a blueberry planting.
  • Wayne County - 1 female in a raspberry planting.
This map shows the counties in the SWD monitoring network where SWD has been found. Mostly in June in 2020.
The distribution map shows that SWD has been found in all trap locations except those in Monroe and Steuben County. First catch occurred mainly in June in 2020.

SWD has now been found in traps set in all but two counties in the monitoring network, but that doesn't mean it's not present in those counties. It is time to take SWD management seriously. If adult SWD are present on your farm, manage them aggressively now that harvests are underway and imminent.

Aggressive SWD management entails 5 key tactics:

  1. Excellent sanitation will reduce SWD populations.

Fruit should be harvested frequently and completely to prevent the buildup of ripe and over-ripe fruit. Unmarketable fruit should be removed from the field and either frozen, “baked” in clear plastic bags placed in the sun, or disposed of in bags off-site. This will kill larvae, remove them from your crop, and prevent them from emerging as adults.

  1. Canopy and water management will make the environment less favorable.

Prune to maintain an open canopy, increase sunlight and reduce humidity. This will make plantings less attractive to SWD and will improve spray coverage. Repair leaking drip lines and avoid overhead irrigation when possible. Allow the ground and mulch surface to dry before irrigating.

  1. Insecticide sprays will kill SWD adults and thereby reduce egg laying:

Insecticide treatments should begin when either regional monitoring alerts about the first SWD trap catch or when highly susceptible fruit crops begin to ripen. Treatments should be applied at least every seven days and repeated in the event of rain. Choose the most effective insecticides with pre harvest intervals that work for your picking schedule.

Rotate insecticides according to their modes of action.

Quick reference guides:

Check the Cornell Guidelines (cropandpestguides.cce.cornell.edu/) for the latest list of approved pesticides. Special needs labels are being sought for NY berries. Always read and follow the pesticide label instructions.

  1. Regular fruit sampling:

At least 100 fruit per block per harvest should be observed for infestation. Talk to your local CCE agent about a monitoring program. Fruit can be inspected for evidence of larval feeding. Small holes in berries where the eggs were laid may leak juice when the berry is gently squeezed; this is especially diagnostic on blueberry. Infested red raspberry fruit may leave a red juice stain on the berry receptacle when the fruit is picked. Fruit with small indents or bruises where the berry surface appears to have flattened or deflated may be damaged.

A salt flotation method, immersing fruit in a solution of 1 Tbsp. (14.8 cc) table salt per 1 cup (236.6 ml) water, may cause larvae to float to surface. At least 100 fruit per block per harvest should be observed for infestation. Suggested methods were adapted for NY growers in Guidelines for Checking Fruit for SWD Larvae in the Field (https://cpb-us-e1.wpmucdn.com/blogs.cornell.edu/dist/0/7265/files/2017/01/SaltFloatation-2kmt284.pdf).

  1. Cool berries immediately:Chilling berries immediately after harvest to 32o – 33o F will slow or stop the development of larvae and eggs in the fruit. U-Pick customers should be encouraged to refrigerate fruit immediately to maintain fruit quality at home.

Learn more about SWD. Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, http://fruit.cornell.edu/spottedwing/.

Thanks go out to:

  • Elisabeth Hodgdon, ENYCHP CCE, who is monitoring Clinton County
  • Andy Galimberti, ENYCHP CCE, who is monitoring Essex County
  • Natasha Field, ENYCHP CCE, who is monitoring Saratoga and Columbia Counties
  • Grace Marshall, NYSIPM CCE, who is monitoring Cayuga, Schuyler and Wayne Counties
  • Sarah Tobin, ENYCHP CCE, who is monitoring Orange County
  • Laura McDermott, ENYCHP CCE, who is monitoring Washington County

Sustained catch of a single male SWD in a trap set in a blueberry planting was found in Erie County. The traps were checked on June 24, 2020. Interestingly, the prior week when first catch was obtained on June 17 there were more SWD caught — one male and two females.

This can sometimes happen if weather conditions are unfavorable, extreme heat and dry conditions, or could result from insecticide applications that were made to manage SWD or other insects. These traps are being monitored by Sharon Bachman, Erie County Cornell Cooperative Extension.

So far, SWD has been caught in 21 of the 23 counties where traps are being monitored across NY State. Sustained catch – two weeks in a row – has occurred in about 11 of those counties.

Fruit is ripening across western NY and becoming susceptible to egg-laying. Brush up on SWD management, http://fruit.cornell.edu/spottedwing/management/ on Cornell Fruit Resources.

Learn more about SWD. Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, http://fruit.cornell.edu/spottedwing/.

One female SWD was caught in a trap set in a blueberry planting in Wyoming County. The traps were checked on June 25, 2020. The crop is developing nicely. It is essential to keep close watch on the stage of ripeness, to know when fruit becomes susceptible to egg-laying — at pink to purple color. These traps are being monitored by Don Gasiewicz, Wyoming County Cornell Cooperative Extension.

Picture of strawberry fruit with an egg-laying site.
Evidence of oviposition into June strawberry found today, 20 June 2019, by Jim O'Connell, CCE Assoc of Ulster County. Notice the delicate white breathing tubes and the small area of sunken, tan tissue where the larva is inside the fruit.

This blueberry planting is immediately adjacent to a large strawberry planting. We know from prior years and reports from other states that when June strawberry harvests are done, the number of SWD caught in traps often spikes. Whether this is coincidence or related to something specific with June strawberries serving as a resource for SWD, we aren’t quite sure. But, suffice it to say, that if you have June strawberries and are also growing blueberries or raspberries or cherries nearby, renovate the June strawberry fields ASAP. Please review methods for doing this effectively on the post by Laura McDermott, Renovate June Strawberry Fields Promptly, https://blogs.cornell.edu/swd1/2018/06/27/renovate-strawberry-plantings-promptly/

SWD Resources

SWD Management, http://fruit.cornell.edu/spottedwing/management/ on Cornell Fruit Resources.

Insecticide Quick Guides for NY State are found here (refresh the page to see the latest version):

SWD Management in Blueberry

SWD Management in Raspberry and Blackberry

Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, fruit.cornell.edu/spottedwing/.

A single female SWD has ushered in SWD management in a blueberry planting in Onondaga County. The offending insect was caught in one of the four traps checked on June 23, 2020. Fruit is starting to color and, as it ripens, will be susceptible to egg-laying. These traps are being monitored by Grace Marshall, NYS IPM Program, Cornell Cooperative Extension.

Across New York, SWD reports are coming in – either first or sustained catch. This is at a time when berries and cherries are ripening up for harvest. This co-occurrence of events places these susceptible crops at high risk of infestation. It will be very important to bring to bear every management tactic and monitoring tactic available to stay ahead of SWD and protect your harvests. Read up on SWD Management, fruit.cornell.edu/spottedwing/management/, on Cornell Fruit Resources.

Pest management for SWD includes:

  • Mowing – to reduce humidity and niches for SWD harborage and to increase sun penetration.
  • Weed management – to reduce humidity, alternate fruiting hosts and harborage and to increase sun penetration.
  • Pruning – to reduce humidity and to increase sun and spray penetration.
  • Monitoring – to know if SWD is present when fruit is ripening.
  • Sanitation – to reduce reproduction harborage and overall SWD population.
  • Cold storage – to slow or kill any eggs and larvae in harvested fruit.
  • Timely application of insecticides – to protect the crop from egg laying.
  • Insecticide Quick Guides for NY State are found here (refresh the page to see the latest version) -
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.

Organic Growers: insecticides allowable in organic production are in the quick guides. Please note, Entrust must be rotated with other organically-approved insecticides in different IRAC groups to prevent resistance developing in SWD against Entrust. One option is Grandevo. We have new information showing it has moderate activity against SWD. The listing on the quick guide has been revised for stone fruit and grapes, but still needs to be updated for berries.

Learn more about SWD. Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, fruit.cornell.edu/spottedwing/.

Not quite everywhere, but all of the Eastern NY network is now at first or sustained catch and all but four counties in the Lake Ontario, Central, Finger Lakes, and Southern Tier regions are at first catch. That’s seven counties reporting first catch, most from traps checked on June 22!

  • Cayuga County had 2 males and 2 females in a raspberry field. Checked June 18.
  • Chemung County had 3 males and 2 females in a blueberry planting. Checked June 22.
  • Columbia County had 2 males and 3 females in a tart cherry orchard. Checked June 22.
  • Orleans County had 1 female in a raspberry field. Checked June 22.
  • Tioga County had 5 males and 3 females in a blueberry field. Checked June 22.
  • Washington County had 1 male and 2 females I a blueberry field. Checked June 22.
  • Wayne County had 2 females in a raspberry planting. Checked June 22.
Photo of a male SWD on a blueberry.
A male spotted wing drosophila (SWD) on blueberry; another likely SWD is in the background.

Fruit across the region is ripening – blueberries, cherries, possibly even raspberries. Other summer fruits like haskaps and June berries are susceptible to SWD. June strawberries could be at risk. Day neutral strawberries will be at risk. Peaches and plums? – pick them before they are deliciously tree ripe and soft.

And now, I’m going to repeat myself.

Pest management for SWD includes:

  • Mowing – to reduce humidity and niches for SWD harborage and to increase sun penetration.
  • Weed management – to reduce humidity, alternate fruiting hosts and harborage and to increase sun penetration.
  • Pruning – to reduce humidity and to increase sun and spray penetration.
  • Monitoring – to know if SWD is present when fruit is ripening.
  • Sanitation – to reduce reproduction harborage and overall SWD population.
  • Cold storage – to slow or kill any eggs and larvae in harvested fruit.
  • Insecticide treatment – Insecticide Quick Guides for NY State:
Photo of a high tunnel with exclusion netting to protect the raspberry crop inside from SWD.
Exclusion netting over high tunnel raspberries will protect them from SWD.

Those who choose not to spray will have to take every measure possible to prevent population build up. Exclusion netting should be the plan for these growers going forward, because without exclusion netting and without insecticide protection it’s impossible to bring sufficient fruit to harvest in years like 2020 when SWD populations build up early and crop development is delayed.

Learn more about exclusion netting, Thinking Exclusion?blogs.cornell.edu/swd1/2020/03/27/thinking-exclusion/

Clean picking and treating with insecticide to “reset the field” is a management tactic used in large-scale commercial blackberry production in North Carolina. You may want to consider that tactic in your raspberry and blackberry plantings, if SWD has gotten ahead of you. It will only work in such fruit crops that continue to flower and set fruit.

Use salt flotation to routinely sample your fields. Read, Guidelines for Checking Fruit for SWD Larvae in the Field.

Renovate June strawberry fields promptly, blogs.cornell.edu/swd1/2018/06/27/renovate-strawberry-plantings-promptly/

SWD Management, fruit.cornell.edu/spottedwing/management/ on Cornell Fruit Resources.

SWD Management in Blueberry

Read this blog, Managing SWD in blueberries at blogs.cornell.edu/swd1/2019/08/02/managing-swd-in-blueberries/ .

Spotted Wing Drosophila IPM in Blueberries from the NE IPM Center SWD Working Group, neipmc.org/go/swdpub2

SWD Management in Raspberry and Blackberry

Read this blog, Managing SWD in raspberries and blackberries at blogs.cornell.edu/swd1/2019/07/17/managing-swd-in-raspberries-blackberries/

Spotted Wing Drosophila IPM in Raspberries and Blackberries from the NE IPM Center SWD Working Group, neipmc.org/go/swdpub1

Learn more about SWD. Knowledge is power! Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, fruit.cornell.edu/spottedwing/.

Thanks go out to

  • Grace Marshall, CCE NYS IPM, who is monitoring the sites in Cayuga and Wayne Counties;
  • Liz Alexander, CCE Chemung County, who is monitoring the sites in Chemung County (she’s a first year CCE educator. Go, Liz!);
  • Natasha Field, CCE ENYCHP, who is monitoring the Columbia County site;
  • Janet van Zoeren, CCE Lake Ontario Fruit Program, who is monitoring the Orleans County site;
  • Barb Neal, CCE Tioga County, who is monitoring the Tioga County site; and
  • Laura McDermott, CCE ENYCHP, who is monitoring the Washington County site.

Sustained catch, that is two weeks in a row, was obtained in two counties in Eastern NY, Ulster on June 19 and June 21 and Albany on June 22. Indeed, SWD catch was prevalent across New York State’s monitoring network in traps checked at the end of last week and early this week.

  • Ulster site 5 had 1 male and 1 female in a blueberry field – fruit is ripening and will need to be protected. Checked June 19.
  • Ulster site 6 had 4 males and 2 females in a raspberry planting – pink fruit will be picked clean and an insecticide applied to reset the field. Checked June 19.
  • Ulster HVL had 5 males and 11 females in a cherry orchard – fruit is ripening and will need to be protected. Checked June 21.
  • Albany had 10 males and 26 females in a raspberry field – ripening fruit will need to be protected. Checked June 22.
Picture of honeysuckle, an early-season host for SWD.
Fruit of tartarian honeysuckle, also considered an invasive plant in NY, can support SWD development.

Are you seeing a pattern? With numbers this high, it will be imperative to begin a spray program to protect fruit. SWD populations have built up just as fruit are beginning to ripen. This translates into a challenging year for SWD management.

Those who choose not to spray will have to take every measure possible to prevent population build up. Exclusion netting should be the plan for these growers going forward, because without exclusion netting and without insecticide protection it’s impossible to bring sufficient fruit to harvest in years like 2020 when SWD populations build up early and crop development is delayed.

Learn more about exclusion netting, Thinking Exclusion? blogs.cornell.edu/swd1/2020/03/27/thinking-exclusion/

Renovate June strawberry fields promptly, blogs.cornell.edu/swd1/2018/06/27/renovate-strawberry-plantings-promptly/

Use salt flotation to routinely sample your fields. Read, Guidelines for Checking Fruit for SWD Larvae in the Field.

Pest management for SWD includes:

  • Mowing – to reduce humidity and niches for SWD harborage and to increase sun penetration.
  • Weed management – to reduce humidity, alternate fruiting hosts and harborage and to increase sun penetration.
  • Pruning – to reduce humidity and to increase sun and spray penetration.
  • Monitoring – to know if SWD is present when fruit is ripening.
  • Sanitation – to reduce reproduction harborage and overall SWD population.
  • Cold storage – to slow or kill any eggs and larvae in harvested fruit.
  • Insecticide treatment – Insecticide Quick Guides for NY State:

Clean picking and treating with insecticide to “reset the field” is a management tactic used in large-scale commercial blackberry production in North Carolina. You may want to consider that tactic in your raspberry and blackberry plantings, if SWD has gotten ahead of you. It works best in such fruit crops that continue to flower and set fruit season-long.

SWD Management, fruit.cornell.edu/spottedwing/management/ on Cornell Fruit Resources.

SWD Management in Blueberry

Read this blog, Managing SWD in blueberries at http://blogs.cornell.edu/swd1/2019/08/02/managing-swd-in-blueberries/ .

Spotted Wing Drosophila IPM in Blueberries from the NE IPM Center SWD Working Group, http://neipmc.org/go/swdpub2

SWD Management in Raspberry and Blackberry

Read this blog, Managing SWD in raspberries and blackberries at http://blogs.cornell.edu/swd1/2019/07/17/managing-swd-in-raspberries-blackberries/

Spotted Wing Drosophila IPM in Raspberries and Blackberries from the NE IPM Center SWD Working Group, http://neipmc.org/go/swdpub1

Learn more about SWD.

Check out the information on Cornell Fruit Resources Spotted Wing Drosophila, http://fruit.cornell.edu/spottedwing/.

Thanks go out to Jim O’Connell, Ulster County CCE who is monitoring Ulster 5 and 6; Lydia Brown, Hudson Valley Research Laboratory, who is monitoring Ulster HVL (traps set in honeysuckle were at first catch this past week, too – one female); and Natasha Field, ENYCHP CCE, who is monitoring the Albany County site.

A single male SWD was caught in a trap set on the edge of a fall raspberry planting in Orange County. This is first catch at this location. These traps are being monitored by Sarah Tobin, Eastern NY Commercial Horticulture Program.

Fall raspberries are not yet ripe, but typically once they are, they are highly susceptible to SWD infestation.

A map showing the current distribution of SWD trap catches, by County.
The current distribution map of SWD trap catches, showing where SWD has been caught by County.

It is striking how different the current SWD trap catch across the network is for Eastern versus Western NY. Reports in for the monitoring network show the counties where SWD has been found on the distribution map, as compared to those where none have yet been caught in traps (gray).

At both trapping sites in Saratoga County, first catch occurred this week. In tart cherry, two male and one female were caught in traps set in the interior of the orchard. In blackberry, two male and three female SWD were caught in a trap set close to the hedgerow next to the planting. These traps are being monitored by Natasha Field, Eastern NY Commercial Horticulture Program, Cornell Cooperative Extension.

Tart cherries are starting to color and will become increasingly susceptible to infestation as ripening continues. Plan now for an effective insecticide program. Review the choices of insecticides for SWD and plan accordingly. Refer to the Insecticide Quick Guides for NY State for stone fruit and grapes www.hort.cornell.edu/fruit/pdfs/swd/treefruit-grape-insecticides.pdf.

A picture of the breathing tubes of SWD eggs on a blackberry.
Breathing tubes of SWD eggs as seen, magnified by a microscope, on the surface of blackberry fruit.

The blackberries are still hard and green and developing, therefore not susceptible to SWD just yet. once ripening begins, fruit will become susceptible to oviposition. Take time to review the insecticide options for berries, at www.hort.cornell.edu/fruit/pdfs/swd/berry-insecticides.pdf.

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