Spotted wing drosophila (SWD) detections have begun earlier this year than in the previous two years the Spotted Wing Drosophila Volunteer Monitoring Network (SWD*VMN) has been active. Now in addition to positive detections in Surry, Randolph, and Rowan Counties, SWD has been detected in southeastern North Carolina blueberries for the first time this year.
On April 5th, five male and five female SWD were captured in traps at the Horticultural Crops Research Station near Castle Hayne, NC. This site is New Hanover 1 in SWD*VMN, and you can see data from last year here. You'll notice that last year, we caught our first fly here on May 9th, a full month later than our first capture this year. You can see all the trap captures from this site, including those from last week and all future dates here.
What do these trap captures mean for growers in North Carolina?
The fact that we are catching flies at several locations throughout the state means that SWD are active. This means that growers should be vigilant for both SWD adults and larvae on their farms. Growers are strongly encouraged to monitor for SWD adults using the same traps we are using (learn how make and use SWD traps here and here). However, we don't have a good handle on how trap captures relate to fruit infestation, which means that growers should also monitor fruit carefully (learn how to sample fruit and identify Drosophila spp. larvae here). If SWD are present on your farm, we are currently recommending a fairly aggressive management strategy, because there is zero tolerance for larvae present in marketed fruit. Contact your county cooperative extension agent or Hannah for SWD management recommendations.
The SWD*VMN is supported by the North Carolina Tobacco Trust Fund Commission, Inc. and the NC Specialty Crop Block Grant Program.
Insect monitoring in NC Blueberries - 2011
Spotted wing drosophila adult trapping data - New Hanover 1