Sustained Catch in Three Counties

Sustained catch has been obtained in three more counties across New York State: Herkimer, Livingston, and Monroe. High numbers of SWD were caught in four traps in Herkimer County! Here are the details of the sustained catch reports:

Herkimer County - blueberry, 23 females and 13 males, total 36 SWD, traps checked on July 20, 2021 by the grower and insects identified by Juliet Carroll, NYS IPM Program. This is an average of 9 SWD per trap, a point at which the blueberry crop is definitely at risk and in need of protection.

Livingston County - blueberry, 1 female and 0 males, total 1 SWD, traps checked on July 22, 2021 by Dave Thorp, Livingston County.

Monroe County - blueberry, 4 females and 6 males, total 10 SWD, traps checked on July 26, 2021 by Janet van Zoeren, CCE Lake Ontario Fruit Program.

SWD has been caught at nearly all the trapping locations across NY. The SWD season is underway and fruit crops ultimately will be infested by this insect, unless good management tactics are in place. Most of these sustained catches were in blueberry fields. Therefore, for blueberries, here's a refresher of resources:

Managing SWD in blueberries from the NYS IPM Program, 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 entails 5 key tactics:

• 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.

• 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.

• 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, such as raspberries and blackberries, are ripening. 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 are on the SWD Management web page, fruit.cornell.edu/spottedwing/management/. Check the Cornell Guidelines for your crop (cropandpestguides.cce.cornell.edu/) for the latest list of approved pesticides. Always read and follow the pesticide label instructions.

• 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.

• Cool berries immediately.

Chilling berries immediately after harvest to 32°F–34°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.

IPM reminders to level the playing field against SWD

1. Mow your fruit plantings, orchards and vineyards.
2. Control weeds within the row.
3. Prune back shady hedgerows and wooded edges.
4. Prune to open the canopy.
5. Calibrate your sprayer.
6. Rotate IRAC modes of action.
7. Immediately put the fresh fruit harvest into cold storage at 33°F-34°F, which can kill SWD eggs and larvae in fruit.