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Month: July 2017

Published on Leave a comment on More SWD being found – cherries at risk

In the last week of July 2017, my program found up to 100 SWD in some of the SWD traps in our raspberry research plot in Geneva, NY. Without a doubt, pressure from SWD and fruit infestation levels will be increasing as the SWD population explodes.

Sampling cherries in 2016 in western NY to check for SWD. None was found, but in 2017 the situation was different.

In addition, fruit crops normally escaping infestation are reporting problems with SWD. Early blueberry varieties are at high risk and the later varieties will be even more prone to infestation. A tart cherry grower in the Lake Ontario region reports a load of fruit rejected by the processor due to SWD infestation.

When harvest dates are close to insecticide application dates, the available insecticides that can be used against SWD on berries or on tree fruit are few because of the needed days-to-harvest intervals. The heavy rains washing off applied materials creates a greater challenge to keeping fruit clean of infestation.

A mild winter; early arrival of SWD; warm, cloudy, rainy weather; abundant fruit; prolonged ripening windows — these likely have created a perfect storm for SWD in 2017. We continue to learn about this pest, what drives it, and what we can do about it. We thought summer raspberries, early blueberry varieties, tart cherries and sweet cherries weren't at high risk, perhaps we need to rethink this in light of this year's situation and be more vigilant in 2018 for conditions that favor SWD infestation in our early fruit crops.

Published on Leave a comment on Blueberry grower reports

Reports from blueberry growers have come in. SWD — caught in traps, found in fruit, and plantings shut down. One of these growers in the Southern Tier of NY, caught a single male in a trap on Sunday, July 23, 2017, and then,

"In a matter of 3 days my 4 traps exploded with SWD. A minimum of 3 females, the same for males, (in each trap). I have been spraying, but the weather is a problem."

For organic growers, managing SWD in blueberries this year will be nigh on impossible. It is essential to rotate insecticide active ingredients (ai), that is: not using the same active ingredient back-to-back, repeatedly. Entrust is the most efficacious organically-approved insecticide against SWD (ai spinosad), but it is essential to rotate with other ai's such as pyrethrin (Pyganic) or azadirachtin (AzaSol) or the biological Grandevo, which aren't as efficacious. The weather, with heavy and frequent rainfall, washes off the insecticides applied, making it necessary to reapply sooner.

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.

For no spray growers, the best approach will be to invest in exclusion netting for a long term solution to protecting the crop. Even early varieties of blueberries have been hit hard in locations where SWD was found early, whereas in prior years these varieties escaped infestation. This underlines the importance of monitoring in your local area, whether with the use of SWD traps or by sampling fruit using salt flotation to detect infestation. Sampling 100 fruit allows you to quickly get a rough estimate of the percent infestation level from the number of larvae detected in those (12 larvae found/100 fruit = 12% infestation).

There is no magic number or percent infested fruit at which a field should be shut down to pickers, for a u-pick or roadside market. Be proactive with customers and make sure they refrigerate or freeze fruit soon after purchase. However, for the processing market, there may be zero tolerance for SWD-infested fruit. And for some direct market growers when infested fruit is found that signals the time to shut down.

Published on Leave a comment on Catching up on sustained catch reports

Sustained catch (two weeks in a row catching SWD) has occurred in several counties: Orleans on June 15 and 22, Niagara on June 28 and 29, Ulster on June 28 and 29, Clinton on July 10, Essex on July 10, and Livingston on July 13.

SWD infestation on raspberry causes fruit receptacles to stain red, druplets get sunken dimples, and leaking fruit sags.

In Essex County the sustained catch had 144 SWD, caught during the week ending on July 10, 2017.

End of July and early August marks a time frame when SWD numbers in berry crops will increase significantly.

Exponential population growth typically occurs in August. Raspberry fruit may begin to show obvious signs of infestation. Blueberries may also become infested and show signs of fruit infestation.

 

Specific findings:

Orleans County - June 15 at a raspberry site 1 SWD caught in 1 of 2 traps. On July 3, there were 3 SWD caught.

Orleans County - June 22 at a blueberry site 2 SWD caught in 2 of 2 traps. On July 5, there were 10 SWD caught.

Niagara County - June 29 at a raspberry site 8 SWD caught in 2 of 2 traps. On July 5, there were 12 SWD caught.

Niagara County - June 22 at a blueberry site 12 SWD caught in 2 of 2 traps. On July 5, there were 5 SWD caught.

Ulster County - June 28 at a raspberry site 48 SWD caught in 4 of 4 traps.

Ulster County - June 29 at a site with both raspberry and blueberry 17 SWD caught in 4 of 4 traps.

Clinton County - July 10 at a site with both raspberry and blueberry 26 SWD caught in 4 of 4 traps.

Essex County - July 10 at a raspberry site 144 SWD caught in 2 of 2 traps.

Livingston County - July 13 at a site with both raspberry and blueberry 6 SWD caught in 2 of 2 traps.

Information is from Tess Grasswitz, Lake Ontario Fruit Program; Jim O'Connell, Ulster County Cornell Cooperative Extension; Amy Ivy and Annie Mills, Eastern NY Commercial Horticulture Program; and Jennifer Damon and Dave Thorp, Livingston County Cornell Cooperative Extension.

Published on Leave a comment on Sustained catch in St Lawrence County

4 female SWD were caught the week ending July 15, 2017 in two traps set near some wild raspberries growing outside a blueberry planting. This is sustained catch at this location. Paul Hetzler, extension educator, St Lawrence County CCE, is monitoring these traps as part of a berry research project.

Female SWD (left) and male SWD (right), viewed through a dissecting microscope after being drown in an apple cider vinegar trap. Note the serrated ovipositor on the female and the dark single spot on each wing of the male.

Although Paul expected to find more SWD this week, often SWD is slow to build up to large numbers, as has been the case this year.  Single digit numbers of total SWD caught in the 2-4 traps set at a location is common in the first two weeks of trapping, with double digit numbers occurring in the third and fourth weeks.

In prior years, blueberry plantings in Central New York haven't had significant levels of infestation until early August, though this year this might occur by the end of July. Fruit can be monitored for infestation by sampling good quality fruit and screening it using a salt flotation assay.

More information on SWD Management is available on Cornell Fruit Resources SWD web pages.

Published on Leave a comment on Sustained catch in Genesee County

14 SWD were caught on July 10, 2017 in two traps set in a raspberry planting. 7 females were in the trap set within the crop; 4 female and 3 male SWD were caught in the trap set on the edge of the planting.

Male SWD on raspberry fruit. Note dimpling on the fruitlet in the upper left corner of the photo - indicative of fruit infestation.

These traps are being serviced by Jan Beglinger, extension educator, Genesee County Cornell Cooperative Extension. Insect identification is being done by Nicole Mattoon, IPM field technician, and Taylere Herrmann, IPM summer technician, NYS IPM Program.

If your berries are ripe and SWD is being caught in your area, it is time to begin management tactics to protect the crop.

SWD management means practicing IPM using the best combination of:

  • trapping to know when SWD has arrived at the fruit planting;
  • carefully monitoring the ripening fruit crop;
  • sanitation — immediate disposal of over-ripe or infested fruit;
  • sanitation — clean harvesting fruit;
  • pruning and weed management to maintain good air and sunlight penetration into the planting;
  • protecting the crop with insecticide treatments or exclusion netting;
  • refrigeration of harvested fruit.

Published on Leave a comment on First catch in St Lawrence County

SWD was confirmed caught on July 8, 2017 from traps set in a blueberry planting in St Lawrence County. 2 female SWD were caught in one of two traps. There are ripening 'Blue Ray', 'Duke' and 'Blue Crop' blueberry varieties in the field, but 'Patriot' is still green at this location.

John Jaenike, Univ. of Rochester, discusses Drosophila biology with Paul Hetzler during an SWD Workshop in 2014.

These traps are being monitored by Paul Hetzler, extension educator, St Lawrence County Cornell Cooperative Extension, as part of his demonstration research on protected culture production of berry crops.

As blueberries ripen and SWD is caught in your area, sample fruit to check for SWD infestation with a salt flotation assay.

Make sure customers know to keep fruit refrigerated, and freeze, process or use fruit as soon as possible after purchase.

Published on Leave a comment on First catch Livingston County

3 SWD were caught in traps checked on July 6, 2017 — 2 female and 1 male were found in the trap set on the edge of the small blueberry planting at this location.

Checking fruit for larva with salt flotation.

Practice these IPM tactics for managing SWD:

  • trapping to know when SWD has arrived at the fruit planting;
  • carefully monitoring the ripening fruit crop — consider salt flotation assays;
  • sanitation — immediate disposal of over-ripe or infested fruit;
  • sanitation — clean harvesting fruit;
  • pruning and weed management to maintain good air and sunlight penetration into the planting;
  • protecting the crop with insecticide treatments or exclusion netting;
  • refrigeration of harvested fruit.

These traps are being serviced by Jennifer Damon for Dave Thorp, extension educator, Livingston County Cornell Cooperative Extension. Nicole Mattoon, IPM field technician, and Taylere Herrmann, IPM summer technician, with the NYS IPM Program are identifying the insects caught in the traps.

Published on Leave a comment on First and sustained catch Wyoming County

First catch in a raspberry planting on July 6, 2017 of 3 female SWD in a trap within the crop and 1 female in a trap set on the edge of the crop.

An egg is nestled under the skin of this raspberry, as shown by the white breathing tube (yellow arrow) on the fruit's surface. The image is highly magnified to see the tiny structure.

Sustained catch on July 12, 2017 of 18 SWD, 8 females and 10 males. Within the crop the trap caught 7 male and 4 female SWD. On the edge of the crop the trap caught 3 male and 4 female SWD.

These traps are being monitored by Don Gasiewicz, extension educator, Wyoming County Cornell Cooperative Extension.

Published on Leave a comment on Sustained catch in Wayne County

Confirmed sustained catch occurred in Wayne County on June 28, 2017 in ripe summer raspberries (2 females caught in two of four traps) and on July 11 in a blueberry planting (1 female SWD in one of four traps).

SWD female caught in Cayuga County on July 8, 2014. Note the large, sclerotized ovipositor.

These traps are being monitored by Nicole Mattoon, IPM field technician, and Taylere Herrmann, IPM summer technician, with my fruit IPM program.

If your berries are ripe and SWD is being caught in your area, it may be time to start insecticide treatments to protect the crop.

Keep in mind the IPM tactics for managing SWD:

  • trapping to know when SWD has arrived at the fruit planting;
  • carefully monitoring the ripening fruit crop;
  • sanitation — immediate disposal of over-ripe or infested fruit;
  • sanitation — clean harvesting fruit;
  • pruning and weed management to maintain good air and sunlight penetration into the planting;
  • protecting the crop with insecticide treatments or exclusion netting;
  • refrigeration of harvested fruit.

Published on Leave a comment on SWD caught at research sites in Oswego County

1 male SWD was caught June 29, 2017 in one of 6 traps set in a 300 acre preserve field research site that has no managed fruit plantings.

1 female SWD was caught July 6, 2017 in one of 7 traps set in a managed cherry orchard (tart and sweet). Harvest is underway at this orchard.

There are no SWD traps in the monitoring network set in Oswego County. These traps are being monitored by Dr. Peter Newell, Assistant Professor, Dept of Biological Sciences, Oswego State University of New York, Oswego, NY, who shared his findings with me. Gabrielle Solomon, undergraduate student working in his lab, services the traps and does the Drosophila identifications.

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