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Orange County, NY: Spotted Wing Drosophila Observed in Sweet Cherry

drosophila_suzukii_largeOn Monday we had the first observation of spotted wing Drosophila (SWD) Drosophila suzukii, in late spring Summit cherry block in Orange County. We did find ovipositional injury (punctures and eggs) with larva present in cherry fruit of Summit (without insecticide). However, in managed Emperor Francis, a blush, yellow / red mid-late season variety, SWD injury was not observed.

Late cherry varieties such as Regina, Sweetheart and Hudson should be protected on a tight program (3-7d) to reduce infestation from SWD as harvest continues.

Only three classes of insecticides are labeled for use to manage spotted wing drosophila on cherry. They include the pyrethroids: Asana XL 0.66EC (esfenvalarate) and Lambda-Cy 1EC (lambda-cyhalothrin); the organophosphate: Imidan 70W (Phosmet); and the Spinosad class: Delegate 25WG (spinetoram) and Entrust 2SC and 80WP (spinosad).

In conventional programs for cherry refer to the DTH chart below to best accommodate harvest. From laboratory studies we have observed chilling of raspberry for 48-72hrs. to dramatically impact survival of larva and egg.

SWD Mgt.: Sweet Cherry.PMEP

SWD Mgt.: Sweet Cherry.PMEP

In traps throughout the state, SWD adults have observed in raspberry and blackberry, favored host of the SWD. Relative to blueberry and strawberry, raspberry and blackberry require considerably more intensive management strategies. In raspberry or blackberry patches where SWD have been captured and or fruit injury has been observed, management should begin at the first available application window to reduce adult populations and egg laying. In these cultivars a tight management schedule of 3-4 days may be needed if populations continue to increase. Rotating plots within a block may be needed to maintain daily harvesting while cleaning the brambles of all fruit to reset management and eliminate eggs and larva in fruit may be an important part of late season management. Removal and complete destruction of infested berries will also reduce newly developing populations to aid in management. Keeping fruit cold (34-38F) directly after harvest will arrest egg and larval development. Prolonged exposure to these low temperatures for 4d will dramatically reduce egg and larva survival.

Mid-Season Raspberry 'Prelude '

Mid-Season Raspberry ‘Prelude ‘

Conventional and Organic Management Options for NYS grown small fruit:
Insecticides labeled in NYS to manage SWD

SWD Egg and respiratory horn on raspberry

SWD Egg and respiratory horn on raspberry

To date, SWD adults have been captured in the Hudson Valley counties of Suffolk, Orange and Ulster in cherry, raspberry, blueberry and blackberry plantings as well as much of the fruit growing regions along Lake Ontario. Given the increasing number of SWD finds we are seeing in the northeast, it would be wise to begin trapping efforts in cherry orchards, brambles and blueberry fields as flies increase from localized to regional populations. Although very little damage has occurred in Hudson Valley fruit, It is likely that SWD damage to small fruit will begin over the upcoming week as adults establish and build in populations in berry patches.

Male SWD (Image. HVRL)

Male SWD (Image. HVRL)

Spotted Wing Drosophila, Drosophila suzukii (SWD) is a vinegar fly native to East Asia. Established in the Eastern US since 2012, it has become an invasive insect pest of small fruit and to a lesser degree, cherry and grape. Information on insect biology.

Traps we are presently using are made of red plastic 16 oz. solo cups and lids with a black band of electrical tape. Traps are baited with apple cider vinegar (ACV), as the attractant killing solution. Approximately 30, 1/8″ holes, are drilled around the top 3/4 of the cup, leaving a 3′ gap to pour out the ACV solution in a strip of 2″ x 2″ netting to access the number of captured flies. A yeast, flour & sugar bait mixed with water is added to a 5 oz. fixed position cup along the top edge.

SWD Egg on Raspberry.

SWD Egg on Raspberry.

SWD Red Solo Cup Trap. Image UNH

SWD Red Solo Cup Trap. Image UNH Cooperative Extension

The Cornell Spotted Wing Drosophila web site hosts a map of the counties in which SWD is being trapped. Updates on presence based on trap findings can be found here.

SWD Identification using key characteristics.

SWD Identification using key characteristics.