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On August 20th, traps being monitored by Bernie Armata, Extension Educator, Herkimer County Cornell Cooperative Extension, caught 5 male SWD. These traps were in a blueberry planting and shortly after receiving the trap catch news, the grower did salt flotation on a fruit sample, confirmed larval presence and shut down harvest.

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.

The good news is the grower was able to harvest 90% of their blueberry crop before SWD arrival.

Bernie adds that, "It would seem that SWD arrive in Central NY a bit later than some other areas of the state, as this has been the case two out of the last five or six years."

SWD populations are building up. Any fruit hanging will be at risk of infestation. Not until late November will the majority of female SWD no longer carry eggs, to prepare for overwintering. If you have fruit in protected culture (high tunnels), be especially vigilant. SWD management during late summer and early fall must include insecticides to protect fruit from infestation, unless effective exclusion netting is being used.

All SWD trapping locations have caught SWD. First trap catch occurred over a nine- to ten-week-long period, from June 8 to August 13. SWD was caught earlier this year than in prior years, but the hot and extremely dry weather across New York State appears to have benefited berry crops, which suffered lower infestation rates in July than might have been expected from the early arrival of SWD.

Distribution map for SWD, as determined by the SWD network operated by 25 Cornell University and Cornell Cooperative Extension scientists in 25 Counties, monitoring 117 traps.
Distribution map for SWD, with data contributed by the SWD network operated by 25 Cornell University and Cornell Cooperative Extension scientists in 25 Counties, monitoring 117 traps.

Twenty-five scientists monitored traps in 25 Counties this year. A total of 117 Scentry traps were deployed in the network, primarily in raspberry (summer and fall) and blueberry. The first trap network site to report SWD trap catch was in Suffolk County, Long Island. At about the same time, SWD was caught at a research location in the Finger Lakes region.

Although SWD might show up around the same time each year in a particular location, this doesn't often hold true. For instance, the location in 2015 at which my program caught SWD first was among the last of our monitoring locations to catch SWD this year.

The long length of time, 66 days, over which first trap catch reports came in from across NY in 2016 and in prior years (56 days in 2015, 56 days in 2014, 76 days in 2013) provides evidence that SWD arrival across NY isn't synchronous. For this reason, in addition to trap catch reports, growers should consider crop maturity and crop susceptibility to infestation when formulating management decisions.

With most of NY in the grips of a drought - abnormally dry, moderate drought, severe drought, and extreme drought as of August 25 - this could keep SWD population growth in check. The US drought outlook shows likely drought removal in the Hudson Valley region, but drought will likely persist in western NY and Suffolk County.

It is easy and fast to check fruit for SWD infestation. Leaky fruit and dull sunken areas on fruit point to infestation. A quick salt flotation assay provides a good measure of SWD infestation in fruit—time well spent. Consult the Cornell Fruit Resources SWD pages for more information on dealing with this invasive pest.

Two male SWD were caught in Steuben County on August 13, 2016 in a trap set within a small planting of raspberry and blueberry; no SWD were caught in the trap outside the planting. The following week, sustained catch occurred with 5 male SWD caught within the planting and 2 male SWD caught in the trap outside the planting. These traps are being monitored by Stephanie Mehlenbacher, association community educator, Steuben County Cornell Cooperative Extension.

This report completes SWD early season monitoring. All New York monitoring sites have caught SWD. Maintain an effective SWD management strategy on late season berry crops.

Four male SWD were caught in traps set in a summer raspberry planting in Clinton County in the week ending July 11, 2016, indicating sustained catch. The following week, high numbers of SWD were caught and enumerated on July 19, 2016—10 male and 15 female SWD in the raspberries.

Traps set in the blueberries at this same location only had 2 female SWD in traps checked on July 19. A similar scenario was seen on another farm in New York where raspberry and blueberry are both grown. This would suggest that raspberry is more attractive to SWD and that traps set in raspberry may provide earlier warning of SWD arrival. This also suggests that raspberry is at higher risk of SWD infestation than blueberry.

Traps at this Clinton County location are being monitored by Lauren Fessler, summer intern, who is working with Amy Ivy, Extension Educator, Eastern NY Commercial Horticulture Program and Clinton County Cornell Cooperative Extension.

First trap catch in Essex County occurred on July 18, 2016 with a very large number of SWD caught in a summer raspberry planting. A total of 49 SWD, 33 male and 16 female, were enumerated in the four traps by Lauren Fessler, summer intern, who is working with Amy Ivy, Extension Educator, Eastern NY Commercial Horticulture Program and Clinton County Cornell Cooperative Extension. It is likely that sustained trap catch has occurred at this location by now.

A large number of SWD were caught during the week preceding August 3, 2016—53 females and 18 males—in traps set in a blueberry planting in Onondaga County. Luckily blueberry harvest at this location is winding down, because SWD populations are building up! These traps are being monitored by Nicole Mattoon, Field Technician, and Juliet Carroll, Fruit IPM Coordinator, NYS IPM Program.

Four female SWD, as seen through a dissecting microscope, that were caught in a Scentry trap. The inset in the middle is a close-up of the females ovipositor.
Four female SWD, as seen through a dissecting microscope, that were caught in a Scentry trap. The inset in the middle is a close-up of a female's ovipositor.

On July 20, 2016 first catch of 7 female SWD was found in a blueberry planting in Seneca County. The following week SWD had been caught again in the traps, indicating sustained catch. Traps at this location are being monitored by Gabrielle Brind’Amour, technician with Greg Loeb’s small fruit entomology program, NYSAES, Cornell University, Geneva, NY.

On July 6, 2016 first catch of 1 female and 3 male SWD was found in a raspberry planting in Orange County. The following week, 2 female and 4 male SWD had been caught in the traps, indicating sustained catch. Traps at this location are being monitored by Tim Lamposona, technician with Peter Jentsch’s entomology program, Hudson Valley Research Lab, Cornell University, Highland, NY.

Two male and 12 female SWD were caught in traps on July 26, 2016 that were set in a blueberry planting in Onondaga County. Much of the planting had reduced crop load due to winter damage. These traps are being monitored by Nicole Mattoon, technician, and Juliet Carroll, Fruit IPM Coordinator, NYS IPM Program.

Although SWD had been caught earlier in an adjacent insecticide timing trial in raspberry with abundant fruit nothing had been caught in the blueberries until now. This underlines how much more attractive raspberry is to SWD than blueberry.

If you have ripe fruit on your farm, take time to monitor, check fruit for infestation, and develop an integrated management plan that includes refrigeration soon after harvest. Populations of SWD will continue to build up through the summer and into the fall.

Sustained capture in traps checked on July 18, 2016, in Genesee County found 10 female and 1 male SWD. These traps are set in a fall raspberry planting in which fruit are just beginning to ripen.

Traps in Genesee County are being monitored by David Russell, Master Gardener, and Jan Beglinger, association community educator, with the Cornell Cooperative Extension Association of Genesee County.

Informed decision-making is best. Read guidelines for dealing with SWD:

  1. Monitoring SWD
  2. Managing SWD

Find this information and more on the Cornell Fruit Resources Spotted Wing Drosophila website.

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