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The SWD monitoring network Counties are all positive for SWD as of last week, August 28, 2015. A lot of SWD are being caught in traps in research sites now with population numbers expected to climb into the thousands before frost knocks them back and forces them into winter diapause.

All sites in NY's SWD monitoring network reported SWD by the end of August. Counties in white did not have traps reporting to the network.
All sites in NY's SWD monitoring network reported SWD by the end of August. Counties in white did not have traps reporting to the network.

Reports are coming in of severely infested fall raspberries. This fall will be especially challenging for fall harvest of susceptible fruits. Blackberries and raspberries are particularly vulnerable and will require intensive management with sanitation and insecticide protection. One sanitation strategy used in California for berries is for workers to crush any fruit that has fallen to the ground, reducing the chance of larvae surviving to grow into egg-laying adults. For insecticides, maintaining good coverage is essential, so keep track of rain events that can wash off insecticide (>0.5 inch) and reapply at the appropriate interval listed on the labels.

Late-season blueberries, peaches, plums and grapes are vulnerable to infestation, though not as susceptible as brambles, it will be wise to examine the crop for infestation. Fruit that is softer than it should be, with dull sunken areas and tiny drops of sap may be infested. Hold marketable fruit samples on white paper towels for a day or so and rotate it to see if it is leaking from tiny pinholes indicative of larval breathing sites. Use salt floatation to float out larvae and assess the relative abundance of larval infestation and severity of the problem. Place 50 ripe, marketable fruit in a plastic bag, cover with salt solution (1 Tbsp salt/cup water) and examine in 15-30 minutes for emerging larvae. Larvae are small 1-3 mm or 1/16-2/16 inch long. More on checking fruit for infestation is in the blog Do my fruit have SWD?

SWDlifecycleInfestations can contribute to sour rot in grapes and fruit decays in other fruit crops. Severely infested raspberries will appear to melt off the plants.

If fruit is still ripening and ripe fruit is infested, clean pick all ripe and overripe fruit and discard it to remove the developing SWD population from the planting. After clean picking and sanitation, apply an effective insecticide to protect the ripening fruit.

Discard infested fruit in clear plastic bags held in the sun to solarize and kill larvae or freeze it. Holding culled fruit in tightly closed plastic bags will prevent SWD adults to emerge from the infested fruit into the environment.

High temperature will dissuade SWD, but hot days this past week in NY have been followed by cool nights which has likely allowed SWD adults to escape the impact of the heat. High humidity is conducive to SWD development, so that factor will also weigh in to make management difficult this fall. The microclimate in the fruit planting can be altered with pruning practices, so plan now to prune for a more open plant canopy in 2016.

Consult the resources in the right hand side bar for more information on SWD.

Two SWD were caught on August 18, 2015 in traps set in raspberry & blueberry in Steuben County. This site is being monitored by Stephanie Mehlenbacher, Steuben County Cornell Cooperative Extension. (GDD = 1776, day length = 13:44)

Only three sites in the NY monitoring network have not yet reported SWD finds. If you have ripe or ripening fruit to be harvested, consider a strict regimen to manage SWD: judicious insecticide applications (tree fruit, grapes, berry crops), immediate refrigeration of harvested fruit, squashing any fruit that falls to the ground, clean picking overripe and unmarketable fruit, weed control, and pruning to maintain an open canopy and promote earlier bearing in brambles.

Three SWD, two female and one male, were caught on August 11, 2015 in traps set in blueberry. The SWD were in the trap set on the edge of the crop. This site is being monitored by Jim O'Connell, Ulster County Cooperative Extension and Eastern NY Commercial Horticulture Program. (GDD = 2019, day length = 14:00)

It is very likely that SWD is present across NY State wherever tender, ripe fruit is found. Consider what your SWD management strategy will be. Make plans for dealing with this introduced, invasive pest in your berry crops by reading up on horticultural strategies that make sense in the era of SWD.

Now found in 25 of 28 (89%) of Counties in the SWD monitoring network, 2015 will be challenging for late fruit crops in NY. Traps have caught SWD two weeks in a row in 22 of the 25 NY Counties reporting SWD finds.

The SWD distribution map for the NY State monitoring network, as of August 17, 2015. Minor modifications were done to the map to show that SWD was found in August and no SWD has been found to date in Columbia, Dutchess, and Steuben Counties, as compared to the online distribution map, to account for those locations where online reports have not been submitted to date. legend
The SWD distribution map for the NY State monitoring network, as of August 17, 2015. Minor modifications were done to the map to show that SWD was found in August in Saratoga County and no SWD has been found to date in Columbia, Dutchess, and Steuben Counties, as compared to the online distribution map, to account for those locations where online reports have not been submitted to date.

Of the 48 monitoring sites across NY, only 5 have not yet caught SWD; 90% of all SWD monitoring sites have positive reports of SWD caught in traps.

Some monitoring network participants are sampling fruit, when SWD is first caught in traps, and checking for infestation with salt floatation.  At first trap catch, most fruit samples have few to no SWD larvae or eggs in a 50-fruit sample. Monitor your fruit for symptoms and signs of SWD infestation using the methods described in the blog, Do my fruit have SWD?

Those sites where SWD hasn't been caught yet are characterized as having fruit that is not yet ripe, such as fall raspberry, or low fruit set possibly due to the cold winter, such as in blueberry.

Some monitoring sites reported high numbers of SWD in late July/early August, the second consecutive week of trap catch - e.g. 83 in Washington County, 40 in Cayuga County. Cooperators are pulling traps once at sustained catch.

Researchers in Greg Loeb's lab, Department of Entomology, Geneva, studying different lures in the Finger Lakes region are now catching 20-40 SWD per trap. Sites in their study with rigorous spray schedules catch less than 10 SWD per trap. Research projects are wrapping up, too.

Our focus is to provide early warning of SWD arrival in NY State. We will continue reporting on the SWD monitoring network until all sites have caught SWD. If you have any questions, suggestions or comments, please let me know.

14 SWD were caught today, August 17, 2015, in traps set in blueberry in Clinton County, 10 males in traps set in the interior of the crop and 4 males in traps set on the edge of the crop. These traps are being monitored by Lindsey Pashow, technician, and Amy Ivy, educator & director, Clinton County Cornell Cooperative Extension. These males may be lonely...? Another review of trap contents on Wednesday will confirm whether females are absent.  Regardless, don't think for a minute that absence of females means your crop is safe. They could be out laying eggs and ignoring the lure of food provided by the traps. Only three Counties in the 29-County network have not yet caught SWD (Columbia, Dutchess, and Steuben). If your crop is ripe - take steps to manage SWD. If your crop is on the verge of ripening - make plans to protect it from SWD. (GDD = 1793, day length = 13:55)

SWD male
SWD male, note spot on each wing.

One female SWD was caught on August 5, 2015 in a trap set in a blueberry planting in Herkimer County. Traps at this location are being monitored by Bernie Armata, Herkimer County Cornell Cooperative Extension Association. (GDD = 1601, day length = 14:18)

To date, only four counties (Clinton, Columbia, Dutchess, and Steuben) have not caught SWD. In these sites, fruit is either unripe or the crop is blueberry, which can be tricky for trap catch with our current traps.

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.
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. Tiny juice droplet on the berry (below and to the right of the top fly) could signify the berry is infested.

Two SWD at one location & one SWD at a second location in Tioga County were caught the week of August 3, 2015. At both locations the traps were in raspberry and are being monitored by Michele Kline, Regional Fruit & Vegetable Specialist, Tioga County Cornell Cooperative Extension. (GDD = 1562 & 1740, day length = 14:10 & 14:09, respectively.)

One male SWD was caught on August 4, 2015 in a trap set in fall raspberry in southern Essex County. The report comes in from Amy Ivy, Clinton County Cornell Cooperative Extension and Eastern NY Horticulture Program. The raspberries at this site are just starting to ripen. (GDD = 1602, day length = 14:24)

In response to Amy's finding, Laura McDermott replied, "The pressure we are experiencing (in the Capital District) right now makes me want growers to be as pro-active as possible. The fact that you found (SWD) in a crop that hasn’t even started harvest yet is significant – and I would advise people to get ready to start spraying. I’ve been getting calls from around the state from folks that are seeing (SWD) that haven’t really been bothered much since 2012."

2015 is going to be a challenging year for SWD management. It is time to take SWD management seriously.

One female SWD was found on August 4, 2015 in a trap set in blackberries in Saratoga County. This report came in from Tegan Matthews, Cornell Cooperative Extension Intern with Laura McDermott, Eastern NY Horticulture Program. (GDD = 1863, day length = 14:19)

The blackberries at this site are almost completely devoid of fruit! But, it looks like SWD will be on hand to infest fruit once it develops unless it is protected with insecticide. Plan on an effective, well timed spray program for your fall berries; refer to the berry insecticide guide for SWD. Make sure you rotate between different insecticide modes of action (or IRAC groups) to prevent insecticide resistance from developing in SWD. Pay attention to all management practices for SWD to lower the risk of fruit infestation.

Two female and one male SWD were caught on Thursday, July 30, 2015, in a trap set in raspberry in Chemung County. Traps in this county are being monitored by Michele Kline, Regional Fruit & Vegetable Specialist, Tioga County Cornell Cooperative Extension. No SWD were caught in a trap set in blueberry at this location. (GDD = 1459, day length = 14:26)

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