A national team of researchers lead by the University of Georgia has released a new guide to organic management of SWD this May, 2018, Management Recommendations for SWD in Organic Berry Crops. The guide details information on non-chemical and insecticide approaches to protect berry crops against SWD.
Controlling SWD is particularly challenging, requiring a rigorous, persistent and diverse management plan. The guide details several management recommendations and suggests using as many control techniques as possible to reduce SWD infestation.
Funding for the research was provided by the USDA National Institute of Food and Agriculture Organic Agriculture Research and Extension Initiative (OREI).
Download the guide in PDF form here, http://www.ipm.msu.edu/uploads/files/SWD/SWDOrganicBerryCrops.PDF.
This post was written be Peter Werts, EcoFruit, IPM Institute of North America, Inc.
During the week ending on June 27, 2018, 6 female and 2 male SWD were captured in two separate Scentry-lure baited traps at blueberry and raspberry locations in eastern Long Island. This is about 2 weeks later than last year’s first interception in Suffolk County. Blueberries are still too unripe to be damaged by SWD. Some raspberries are near ripening.
After checking about 20 raspberries, no sign of SWD egg laying or damage was found in fruit. These particular blueberry and raspberry sites have surrounding woods and both traps that captured the SWD were placed on the border rows near the woods.
No SWD have been captured in traps placed in other locations (in the raspberry and blueberry fields, in a blackberry planting, and in a grape vineyard).
At this time the SWD population appears to be very low and sporadic. Insecticide applications may be necessary when fly populations are high which usually occurs from late July onward.
This post was written by Dr. Faruque Zaman, entomologist, Suffolk County Cornell Cooperative Extension, who is monitoring SWD traps in Suffolk County, Long Island.
A reminder that there will be a workshop on SWD in Chemung County on Tuesday July 10th, 2018, from 9:30 to 11:00 am. Cornell Cooperative Extension (CCE) of Chemung and Tioga Counties cordially invite all interested regional fruit producers to this meeting, Spotted Wing Drosophila Update and Discussion for Fruit Producers.
The workshop will be held at the Waverly Village Hall, Meeting Room, at 32 Ithaca St, Waverly, NY 14892.
Shona Ort, Agricultural Development Specialist, CCE of Chemung County, is organizing this event. To register, contact Shona Ort of CCE Chemung at 607-734-4453 ext 227 or email@example.com.
Two informative presentations, followed by open floor discussion, will round out your knowledge of SWD and it's management.
Dr. Julie Carroll, Fruit IPM Coordinator, New York State IPM Program, will provide a general overview in, Spotted Wing Drosophila: what we know and what we don’t
what is it?
how do I know it's SWD?
what fruit can SWD attack?
when does SWD arrive?
how do I manage it?
Dr. Dara Stockton, Postdoctoral Associate with Dr. Greg Loeb’s lab, Dept. of Entomology, will provide a comprehensive research overview in, Current Research on SWD control in Central NY
improving insecticide applications
Join a discussion with growers to wrap up your knowledge of SWD to take back to your farm!
Cost to attend is free of charge! Please pre-register with Shona Ort, at 607-734-4453 ext 227 or firstname.lastname@example.org to ensure we have enough space, handouts, and refreshments.
For a second week in a row, SWD were caught at a berry farm in Ulster County. Two females were caught, one each, in two traps set inside the planting during the week ending on June 28, 2018. A 20-berry fruit sample was collected and no SWD eggs were found in the fruit. An insecticide was applied to the crop after first catch was obtained last week.
At a second farm in Ulster County, first catch was seen with a single female SWD caught in one trap set in a raspberry planting; the trap on the edge of the planting caught zero SWD. Two traps set in blueberries at this location caught zero SWD.
No insecticides have been applied to this planting, yet. A 20-berry sample of raspberries was collected and 3 of the ripest fruit had eggs. Most fruit aren't quite ripe.
Strawberry renovation is a critical, but often overlooked part of growing June bearing strawberries. This year, with SWD numbers climbing, it’s even more important to remove fruit leftover in the field as quickly as possible. Otherwise, this fruit can serve as a food and reproductive resource for SWD population growth.
The task that creates a lag in the renovation process is the 2,4-D application. Most growers want to apply this herbicide all at once, so early berries are forced to wait weeks for the late varieties to finish — and in the case of ‘Malwina’, growers could delay renovation for more than a month. This tactic leaves a continuous supply of unharvested, cull fruit that SWD can develop in. A further delay is due to 2,4-D needing to be taken up by the leaves — mowing is delayed for 5 days to allow the weeds to absorb the herbicide. Given this added delay from choosing 2,4-D, growers need to make sure the weed species in their field are vulnerable to 2,4-D. If not, don’t delay renovation to use an ineffective herbicide, choose an alternate herbicide, and mow the planting as soon as picking is finished.
Whenever possible, mow the variety as soon as harvest is done. Be aware that mowing a water- or heat-stressed field can result in poor re-growth. Therefore, make sure the plants are well watered prior to mowing. If temperatures are above 90 degrees and you cannot irrigate, mowing should be delayed. If irrigation is not possible, consider skipping the mowing — but still renovate by narrowing the rows and throwing some soil up over existing crowns.
When strawberry fields go out of the rotation, remove them from production as soon as possible by tilling and then seeding a cover crop or a late season vegetable. If you cannot till the field, then mow it close to the crown or cultivate aggressively to help crush and dry down the remaining berries. This will help destroy this resource and limit SWD population growth in the remnant fruit.
Renovation Process – Immediately after Harvest is Finished
1. Ensure the field has adequate soil moisture.
2. Apply 2,4-D if needed.
3. Wait 5 days after 2,4-D is applied to mow. If 2,4-D is not used, mow immediately after picking.
5. Narrow the rows, cultivate middles of wide rows. Throw ½” of soil over remaining crowns.
6. Apply pre-emergent herbicide (ie Sinbar – make sure to read labels as some varieties are sensitive).
Two female SWD were caught in one of two traps set in an Amelanchier hedgerow immediately adjacent to a June bearing strawberry field during the week ending June 25, 2018. The two other traps at this location are inside exclusion netting over a blueberry planting and caught zero SWD. These traps are being monitored by Laura McDermott, Eastern NY Commercial Horticulture Program, Cornell Cooperative Extension.
Strawberry harvest is winding down and there is concern about strawberry renovation practices and potential spillover of SWD into nearby fruit from cull strawberries. Blueberries, raspberries and cherries are ripening and harvests are beginning across New York. Population levels are still low and, so far, no sites are at sustained catch. In addition, few counties across New York have caught SWD — keep an eye on the NY distribution map, because things may change rapidly in the coming week.
It is time to plan your insecticide program for managing SWD. Take this time to determine what insecticides will best fit your overall management program and markets.
What has held back the trap catch this season?
SWD first catch occurred very early this year, but sustained and subsequent increases in trap catch didn't materialize. Environment may have played a roll — weather had intermittent heat waves in May, June was dry, and nights were cool. Last year's serious SWD infestations in blueberries and tart cherries may have made growers more vigilant and willing to invest in insecticide sprays early, keeping populations down.
Why does the SWD population explode?
You can do the math. Let's think optimum conditions for SWD development. A single female can lay around 350 eggs during her lifetime, about 15 per day. The egg to adult phase of the life cycle takes as little as 6 days. So, one female in one day can result in 15 more adults 6 days later, and, during those 6 days, she will have laid another 90 eggs. 6 days after that, those 90 eggs will all be adults. Half of the 105 adults will be females, capable of laying ~350 eggs during their lifetimes...that's 18,375 eggs. A typical life span for SWD is 3 to 9 weeks and there are estimated to be about 10 generations per year in the US, depending on climate.
A single female SWD was caught in one of four traps set in a fall raspberry planting in Ulster County during the week ending June 21, 2018. This trap was set on the edge of the planting next to a blueberry field. A second site in Ulster County with four traps caught zero SWD this week. Jim O'Connell, Ulster County Cornell Cooperative Extension, is monitoring these traps.
Summer raspberries, early season blueberries, sweet and tart cherries are starting to ripen across New York. Depending on variety and location, some sweet cherry blocks are ripe.
As fruit ripens and SWD shows up, it's time to prepare to protect fruit with the best of cultural practices and an insecticide program.
Once fruit is ripe, begin an insecticide program to protect fruit from infestation. More on management tactics can be found on the Cornell Fruit Resources SWD Management page.
One female SWD was caught in a trap set in a sweet cherry orchard in Columbia County during the week ending June 18, 2018. Three other traps at that orchard, two on the orchard edge and another within the orchard, caught zero SWD. These traps are being monitored by technician Natasha Field, working with Laura McDermott and the Eastern NY Commercial Horticulture Program. This cherry block is an early variety and is starting to color.
Two female SWD were caught in traps set in a raspberry planting in Schuyler County during the week ending June 18, 2018. Two other traps set on the edge of the planting and four other traps in an adjacent blueberry planting caught zero SWD. These traps are being monitored by Nicole Mattoon and Ryan Parker, technicians working with Juliet Carroll in the NYS IPM Program. Raspberry fruit are still green at this location.
SWD numbers are still low to non-existent across the Cornell Cooperative Extension SWD trap network trapping locations. Fruit is still, for the most part, immature. However, June strawberry season is underway and a few ripe raspberries were seen in a planting of selections from Courtney Weber's small fruit breeding program, Horticulture, Cornell University.
Once fruit is ripe, it will be important to put a spray program into place. Recent research in Washington State on modeling population growth of SWD suggests that spraying with the most efficacious material early on will knock down the population, slow population growth over time, and make for easier control, possibly with fewer sprays (thus less costly) as the season progresses.
As with any management program, the more cultural tactics that are in place to thwart SWD, the better:
removing overripe and damaged fruit
mowing and weed control
pruned and open canopies
judicious irrigation; no leaking irrigation equipment
postharvest cooling and refrigeration at around 32° to 33° F
A single male was found the week ending June 11, 2018 in one of four traps set in a red raspberry planting in Cayuga County. The trap that caught the male SWD was set in the interior of the 8-row planting. These traps are being monitored by Nicole Mattoon and Ryan Parker, with Juliet Carroll, Fruit IPM Coordinator, in the NYS IPM Program, Cornell Cooperative Extension.
Red raspberry fruit at this site are still green and, therefore, not at risk of infestation. However, next to the raspberry planting are ripening June strawberries. June strawberry typically escapes injury from SWD in New York. This may be because populations are low to non-existent during the June strawberry harvest season. Another reason June strawberries may escape SWD injury could be the use of insecticides to control other insects, such as spittlebug, tarnished plant bug, or strawberry sap beetle.
As raspberry fruits develop and ripen, take time to mow row middles, eliminate weeds from within the row, and thin canes as described in the blog on pruning caneberries. All these tactics will reduce humidity in the planting, increase sun penetration, hasten drying of foliage and fruit, and promote spray penetration. SWD prefer humid environments.