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On October 30, 2013, in Bridgeton, NJ at the Rutgers Agricultural Research and Extension Center, the Northeast Spotted Wing Drosophila IPM Working Group Meeting will be held from 8:00am to 5:00pm to provide updates on this invasive insect and to set and rank priorities for research, extension, education, and regulatory needs to address its impact on agriculture in the Northeast. Funding from the NE IPM Center will defray a portion of travel expenses to support attendance by commercial growers, industry, extension, and research personnel. A Spotted Wing Working Group block of rooms for October 29 and 30 with a discounted rate of $109.00 per night is being held until October 8 at the Courtyard Marriott, 325 Rowan Boulevard, Glassboro, NJ 08028. If you plan to attend the meeting, contact Laura McDermott, The agenda includes speakers from the academic and grower communities from Michigan to North Carolina, with information on

  • Status, monitoring and management in Michigan
  • Status, monitoring and management in North Carolina
  • Overwintering biology and alternative hosts
  • Olfactory cues and chemical control
  • Trap improvements, phagostimulants and behavioral control
  • Visual cues and behavioral control
  • Biological control
  • Monitoring and management in caneberries

Review the SWD 2012 Priorities and send input before the meeting. Your hosts are

Dean Polk shares information on SWD impacts on blueberries with the 2012 SWD IPM Working Group.


Typically, SWD trap catch continues to increase - hundreds/week - peaking in late fall. In Oregon and Washington, SWD counts in traps have about doubled each week over the last four weeks; the pressure is the highest experienced since SWD's introduction to that region in 2009. In North Carolina, where SWD arrived in 2010, high numbers are being caught in traps with fruit infestation nearing 100%. In Rhode Island, where SWD arrived in 2011, late season trap counts in the thousands are derived from an aliquot taken of the total trap contents. First found in 2012 in Colorado, this year it's across the state in very damaging numbers. Is this because as fruit quality declines traps become more attractive to SWD? Is it because adult SWD can live for 20-30 days and during that time can lay >350 eggs so that, by end of summer and into fall, there has been an exponential explosion in population numbers? Answers to these questions and more will be discussed in November by entomologists at a National SWD meeting of the The USDA Multistate Project: SWD Biology, Ecology, and Management, covering these four focus areas:

  1. Biology and ecology of SWD and how it may vary by location, plant host, and season.
  2. Reliable, easy-to-use traps, lures, and methods for monitoring SWD adults and larvae.
  3. Laboratory and field research on developmental parameters and temperature tolerance limits to develop and validate a degree-day model.
  4. Effective cultural, biological, and chemical control tactics for sustainable IPM plans for at-risk crops in the US.

The spotted wing drosophila trap network provided first trap catch data to generate a NY distribution map. Cornell Cooperative Extension personnel participating in the trap network alerted growers to protect their crops when SWD was found in their area. Overall, SWD arrived in NY later in 2013 than it did in 2012 and this may have spared some late-maturing varieties of fruit. Four Counties reported first trap catch in June (dark blue), 19 Counties reported first trap catch in July (dark purple), and three Counties reported first trap catch in August (light purple). Two counties did not find SWD in traps. In August, traps set for SWD were catching hundreds to thousands of other fruit flies, making reading traps tedious and time-consuming. A big "Thank You" goes out to everyone who participated in the NY SWD trap network.

Suggested ways for checking fruit for SWD infestation, include looking for egg breathing tubes, finding leaking pinholes, and floating out the larvae.

Egg breathing tubes You'll need a good pair of eyes and 20x magnification. Fruit on which this technique works fairly well include blackberry, cherry, black raspberry, dark plum and grape varieties, and probably nectarines. Looking for breathing tubes on fruit that is fuzzy (peach, red raspberry), has a waxy bloom (plums, grapes), or is light yellow in color may not be worth the effort. Blogs with breathing tube pictures: SWD in plums, Monroe County - first report, and Oviposition in blackberryA word of caution – I've noticed that once the egg has hatched (12 to 72 hours after laying) the breathing tubes may be shed from the fruit and, therefore, won't be visible. After hatch, what remains on plum, blueberry and other relatively thick-skinned fruit is a pinhole through which the larva periodically breathes as it pauses from feeding. The soft skin and drupelets of blackberry and raspberry collapse in response to larval feeding and the pinhole is less apparent.

Leaking pinholes  On tougher skinned fruit (plum, blueberry, cherry, grape) gently squeezing the near-ripe to ripe fruit may cause a dewdrop of juice to leak through the pinholes that are associated with oviposition and larval development. Fruit that appears sound but from which leaking juices are noticed can be a sign that SWD may be developing in the fruit. Dried drops of juice seen on leaves below a fruit cluster or on fruit in the field are also signs of possible SWD infestation, especially if no bird damage, cracking or other obvious signs of damage are seen on the fruit.

Floating out the larvae  The salt floatation method can be used to quickly assess larval infestation in fruit. This method works better with the soft-skinned fruit, such as blackberry and raspberry. It can be used on blueberry, though the skins may trap the larvae and possibly affect the test results. On larger fruit, such as cherry, peach, and plum, this technique may not work very well. Dissolve 1 Tbsp (~15 cc) table salt in 1 cup (~250 ml) water. Place about 100 fruit in a Ziploc bag or a crisper-type container and add the salt solution. Gently crushing the fruit may help release the larvae. After one hour, examine the salt-solution-immersed fruit for the presence of larvae (white, ~2-4 mm long). The fruit sample may be split into two parts. One part used immediately in a salt floatation test. The other part kept for 3 days to allow eggs to hatch and larvae to develop prior to doing the salt floatation test. (Keep the fruit covered during the 3-day incubation, so it is not contaminated by ambient vinegar flies, and keep it on paper towels or a sponge to absorb liquid, so the larvae don't drown.)

Spotted wing drosophila adults can be seen cavorting on berries. Populations of this insect are exploding and it will become increasingly easy to see the fruit flies on berries in berry plantings. Tim Martinson, Dept of Horticulture, Cornell University, reports finding SWD on essentially every blueberry on the three bushes in his backyard and I have seen SWD adults on blackberry fruit and day neutral strawberry fruit. It is essential to cull overripe and damaged fruit from plantings and maintain insecticide coverage to protect fruit.

A male spotted wing drosophila (SWD) on blueberry; another likely SWD is in the background.
A male spotted wing drosophila on blackberry can be seen near the center of the photograph. Another male stretches his wings while standing on a berry's stem at left.
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