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Spotted Wing Drosophila Update: 8/29/2014

SPOTTED WING DROSOPHILA UPDATE: AUGUST 29, 2014

Click on photo to enlarge.

David Handley, Vegetable & Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila (SWD) captures continue to rise in most of our trapping locations this week, leading to some of the highest numbers we’ve seen this year. The highest SWD captures occurred in Wales and Bowdoinham where, for the first time this season, we have caught over 100 SWD in a week. Gray, Dresden, Turner, Limington, Monmouth and Poland Spring also had fairly high counts (more than 10). Based on what we know about this insect so far, if more than 3 flies are caught in a single week, or more than one fly is caught over two or more consecutive weeks, a regular spray schedule (about every 7 days) is recommended to protect any ripening fruit in that location. If SWD captures continue to increase or any larvae are found in fruit, a 5-day spray schedule would be recommended. We have started finding raspberry fruit infested with SWD larvae in some fields where overripe fruit was prevalent or the planting had not yet been sprayed.

Town Spotted Wing Drosophila weekly trap catch 8/29/14
Springvale 0
Limington 11
Limerick 0
Wells 3
Cape Elizabeth 4
Buxton 1
Gray 57
Bowdoinham 163
Dresden 20
Warren 0
Oxford 0
Farmington 8
Livermore Falls 1
Mechanic Falls 0
Poland Spring 10
Turner 20
Monmouth 13
Wales 250
Fayette 0
Burnham 3
Thorndike 6

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                           1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

The University of Maine is an equal opportunity/affirmative action institution.

Image Description: Insects in Spotted Wing Drosophila Trap

Spotted Wing Drosophila Update: 8/15/2014

SPOTTED WING DROSOPHILA UPDATE: 8/15/2014

Click on photo to enlarge.

David Handley, Vegetable & Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Although spotted wing drosophila captures remain relatively low through most of the state, we are finding the flies in more locations this week. We caught single flies in traps in Wells, Mechanic Falls, Springvale, Fayette and Wales. Two to six flies were caught in our traps in Limington, Gray, Cape Elizabeth, Turner, Bowdoinham, Dresden, Livermore Falls, Farmington, Monmouth, Thorndike, and Burnham. Although we have not yet caught more than six flies in a week at any site, any more than one fly in two consecutive weeks would be cause to recommend a spray to protect any ripening fruit in that location.

Recent weather fronts have been moving into Maine from the south. This may cause a sudden increase in spotted wing drosophila numbers, because we strongly suspect that the flies can travel up on storm fronts.

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                            1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Image Description: Spotted Wing Drosophila Larvae in Raspberry

Spotted Wing Drosophila Update: 8/8/2014

SPOTTED WING DROSOPHILA UPDATE: 8/8/2014

Click on photos to enlarge.

David Handley, Vegetable & Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila captures remain low throughout most of the state this week. No flies were found at most of our trap sites. We caught single flies in traps in Levant, Limington, Buxton and Gray. We caught six flies in our Turner locations, the most we have caught in a single week this season, and enough that we would recommend a spray to protect any ripening fruit in that location. We have not yet had any reports of fruit infested with larvae. Other New England states continue to report captures of spotted wing drosophila in traps, but counts have been low.

If the population growth of spotted wing drosophila follows a similar trend as the past two years, we expect populations to start to build rapidly in the next two to three weeks. Check traps every couple of days for the spotted wings of the male flies. Start protective sprays on any berries that have begun to ripen once more than one spotted wing drosophila is caught in a trap in a week, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.

Products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®. Check product labels for rates, post-harvest intervals and safety precautions. Keeping the fields clean of over-ripe and rotten fruit can also help reduce the incidence of this insect.

We have a new supply of the spotted wing drosophila fact sheet series from Pennsylvania State University covering, biology, identification and management. Contact us if you would like copies.

A simple monitoring trap for spotted wing drosophila:
The trap body is made from a 16 ounce red plastic cup (we use Solo Brand P16RLR). You’ll need one that has a tight fitting lid (we use Solo Brand 626TS). Using a 1/8” hole punch (available through art suppliers) punch about 15 holes in a row around the cup just under the lip about 1/2” apart. Leave about 2” of the diameter of the rim with no holes so that liquid can be poured in and out. Punch a second row of holes just under the first row, to give you a total of 30, 1/8” holes. Use a black permanent marker to paint a 1/2” wide black strip around the cup under the rim, right over the holes you punched. To support the trap, cut a wooden tomato stake down to about 30”. Attach a 4” or larger hose clamp near the top of the stake to act as a cup holder for the trap (we just punched a hole in the metal band of the hose clamp and attached it to the stake with a flat headed wood screw). Place the trap holder in a shady, moist place in or near the fruit planting, with the cup height about 18” off the ground. Fill the trap with 4 to 6 ounces of apple cider vinegar, water + sugar + yeast, or whatever bait you prefer. It is best to add a few drops of unscented soap to break the surface tension of the liquid. Place the lid on the cup to keep rain and critters from getting in, and place the trap in the holder. Adjust the hose clamp so that the trap fits in snugly but the trap holes are not covered up. Empty and re-bait the trap every week. Do not pour out the old bait on the ground near the trap, as this will draw flies away from it.

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                              491 College Avenue
Monmouth, ME 04259          Orono, ME 04473
207.933.2100                           1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Image Description: Male and Female Spotted Wing Drosophila Flies

Image Description: drosophila trap

Spotted Wing Drosophila Update: 8/1/2014

SPOTTED WING DROSOPHILA UPDATE: 8/1/2014

Click on photos to enlarge.

David Handley, Vegetable & Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila captures continued to be low and erratic this week. No spotted drosophila were found at most of our trap sites; but we also caught four flies in our Turner and Wales locations, the most we have caught in a single week this season. We caught two flies in traps in Thorndike and Farmington this week, and single flies in traps in Bowdoinham, Warren and Livermore Falls. We have not yet had any reports of fruit infested with larvae. The other New England states are all now reporting captures of spotted wing drosophila in traps; but like us, the counts have been low.

If the population growth of spotted wing drosophila follows a similar trend as the past two years, we expect populations to start to build rapidly in the next two to three weeks, especially if conditions remain warm and humid. Set out traps, if you haven’t already, and examine them every couple of days. Start protective sprays on any berries that have begun to ripen, once more than one spotted wing drosophila is caught in a trap, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.

Products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®. Check product labels for rates, post-harvest intervals and safety precautions. Keeping the fields clean of over-ripe and rotten fruit can also help reduce the incidence of this insect.

We have a new supply of the spotted wing drosophila fact sheet series from Pennsylvania State University covering, biology, identification and management. Contact us if you would like copies.

A simple monitoring trap for spotted wing drosophila:
The trap body is made from a 16 ounce red plastic cup (we use Solo Brand P16RLR). You’ll need one that has a tight fitting lid (we use Solo Brand 626TS). Using a 1/8” hole punch (available through art suppliers) punch about 15 holes in a row around the cup just under the lip about ½” apart. Leave about 2” of the diameter of the rim with no holes so that liquid can be poured in and out. Punch a second row of holes just under the first row, to give you a total of 30, 1/8” holes. Use a black permanent marker to paint a ½” wide black strip around the cup under the rim, right over the holes you punched. To support the trap, cut a wooden tomato stake down to about 30”. Attach a 4” or larger hose clamp near the top of the stake to act as a cup holder for the trap (we just punched a hole in the metal band of the hose clamp and attached it to the stake with a flat headed wood screw). Place the trap holder in a shady, moist place in or near the fruit planting, with the cup height about 18” off the ground. Fill the trap with 4 to 6 ounces of apple cider vinegar, water + sugar + yeast, or whatever bait you prefer. It is best to add a few drops of unscented soap to break the surface tension of the liquid. Place the lid on the cup to keep rain and critters from getting in, and place the trap in the holder. Adjust the hose clamp so that the trap fits in snugly but the trap holes are not covered up. Empty and re-bait the trap every week. Do not pour out the old bait on the ground near the trap, as this will draw flies away from it.

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                              491 College Avenue
Monmouth, ME 04259           Orono, ME 04473
207.933.2100                            1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks

 

Image Description: Male and Female Spotted Wing Drosophila

Image Description: drosophila trap

Spotted Wing Drosophila Update: 7/24/2014

 

SPOTTED WING DROSOPHILA UPDATE: 7/24/2014

Click on photos to enlarge.

David Handley, Vegetable & Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila (SWD) captures continue to be low this week. Single female flies were caught in traps in Buxton, Turner and Thorndike this week. A single male SWD was caught in Turner. We also have reports of flies being caught in New Hampshire, Connecticut and New York, but also in relatively low numbers.

We expect populations to start to build rapidly in the coming weeks as more food (fruit) becomes available for the flies, especially if conditions remain warm and humid. Now is the time to set out traps, if you haven’t already. Start protective sprays on any berries that have begun to ripen once more than one spotted wing drosophila is caught in a trap, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.

Last year, populations did not reach damaging levels until late August; but weather conditions can alter how quickly the flies will build up. Frequently repeated insecticide sprays (1 to 3 times per week) are often needed to prevent infestations once the insect is present in a field. Products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®. Research suggests that adding table sugar to group 4A insecticides, such as Assail®, may improve their effectiveness. The recommended rate would be 1-2 lbs. sugar per 100 gallons of spray. Please check product labels for rates, post-harvest intervals and safety precautions. Keeping the fields clean of over-ripe and rotten fruit can also help reduce the incidence of this insect.

There is a good fact sheet series on management of spotted wing drosophila from Penn State Extension at: http://extension.psu.edu/plants/vegetable-fruit/fact-sheets/spotted-wing-drosophila-1.

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                              491 College Avenue
Monmouth, ME 04259           Orono, ME 04473
207.933.2100                            1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Image Description: Male Spotted Wing Drosophila

Image Description: Spotted Wing Drosophila Larvae in Blueberry

Fruit Growers Alert 7/3/14: First Male SWD in Maine Wild Blueberry Field Caught this Week!

Fruit Growers Alert – July 3, 2014

FIRST MALE SWD IN MAINE WILD BLUEBERRY FIELD CAUGHT THIS WEEK!

We caught our first male spotted wing drosophila (SWD) in a commercial blueberry field in Blue Hill. The traps were put out last week and collected on Monday, June 30, 2014. However, the 15 other fields scouted had no SWD caught. The fruit in the mid-coast wild blueberry fields are just starting to turn blue and thus are susceptible to SWD, and so my recommendation is for all growers to get their traps out as soon as possible.

Frank Drummond
Professor of Insect Ecology/Entomology
University of Maine

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

2013 Spotted Wing Drosophila Summary for Maine Berry Growers

2013 Spotted Wing Drosophila Summary for Maine Berry Growers

David Handley, Vegetable & Small Fruit Specialist
James Dill, Pest Management Specialist

The spotted wing drosophila (Drosophila suzukii) is an insect invasive to Maine that was first captured here in the fall of 2011.  Based on crop damage in other parts of the country and our own experience in 2012, we know that this insect poses a serious threat to most of the soft fruit crops we grow here, including raspberry, blackberry, blueberry and strawberry. During the summer of 2013 the University of Maine Cooperative Extension Pest Management Program set up drosophila traps in berry fields around the southern, central and coastal regions of the state to monitor the presence and activity of this insect.

The traps were 16 oz. red plastic cups with 30, 1/8” holes punched under the rim to allow the flies access.  A 1/2” wide band of black was painted just under the rim of the cup to increase its visual attractiveness.  The cups were topped with a tight fitting plastic lid and mounted on 4’ tomato stakes fitted with 4” hose clamps to act as a cup holder.  Four to six ounces of bait/killing solution (a mixture of cider vinegar and alcohol) was poured into each trap. A 60 ml plastic specimen cup containing a second bait consisting of water, sugar, flour and yeast was then placed within the trap to further increase its attractiveness.    We placed traps either within the crops or in a wooded area near the crops, knowing the insect prefers humid, shaded areas.   We emptied the traps weekly and restocked them with fresh bait.  The insects captured in the traps were brought back to our lab at Highmoor Farm in Monmouth to be identified.  Many different species are attracted to these traps and proper identification, while time consuming, is essential.  As populations increased we informed growers through our IPM newsletter, blog and webpage, hoping to keep the pest as well managed as possible throughout the summer.

In 2013, the first spotted wing drosophila were caught in Warren and Wells on July 19. With the exception of trapping sites in Warren and Bowdoinham, captures were very low, just a few flies per trap, and scattered, most sites having no flies, until the third week of August.   At that point we began catching low numbers of flies at nearly all locations, including Wells, Limington, Limerick, Springvale, Cape Elizabeth, New Gloucester, Poland Spring, Mechanic Falls, Wales, Livermore, Bowdoinham, and Dresden. Traps in wild blueberry fields in Hancock and Washington counties were also catching flies at this point, but also in low numbers.  By the end of August, our Monmouth, Farmington and Oxford sites had also captured flies.  Trap captures generally remained low (0 to 20 flies/trap) with occasional small flare ups (20 to 100 flies/trap) until the first week of September.  At that point numbers rose fairly consistently in nearly all locations, with weekly trap counts ranging from just a few flies to nearly 1,000. Raspberry and blueberry fruit infested with the small white larvae were being reported.  The highest numbers of flies continued to be found in the most southern and coastal sites.  By the end of October many sites were catching flies well into the thousands (14,000 during one week in Limerick) while some caught only a few flies. At this point flies were readily visible around ripe fruit in many fields and larvae were found infesting most of the fruit in any plantings that had not been sprayed.   At the end of the season we found that a trap maintained for us by a grower in Caribou had caught three flies.

Similar to the 2012 season, growers using insecticides to control spotted wing drosophila found that weekly sprays appeared to provide adequate control when populations remained relatively low (0-10 flies/per week). However, as fly populations expanded, growers found that twice weekly sprays were needed to keep larvae out of the fruit.  Growers used Entrust®, Delegate®, Brigade®, Bifenthrin®, Hero®, Mustang Max®, and/or malathion insecticides, and most found that these products usually offered adequate control if applied on a frequent basis.  Growers who did not apply pesticides saw near total crop loss, following the arrival of spotted wing drosophila in their fields.

Spotted Wing Drosophila Trap Captures 2013 (Excel)

Spotted wing drosophila trap catches remained relatively high throughout the remainder of the season, with dips in late September and early November, which may correlate with dry periods. As in 2012, the highest trap catches occurred late in the season, well after most of the crops had been harvested or lost to frost.  The lack of food likely make the traps more attractive, at least partially accounting for the increased catch, but this reiterates that high numbers of flies survive long after killing frosts have occurred.   By the end of November, populations finally dropped significantly, suggesting that the flies were now entering the over-wintering stage.

Spotted wing drosophila overwinter as adults (flies).  Any time the air temperatures exceed 45ºF for more than a few hours, it is likely that some adults will start becoming active.  The winter of 2013-14 has been one of the coldest in recent memory, and it will be interesting to see how well the flies come through it.  However, it would be unwise to assume that we will not be seeing many flies this summer because of the cold winter.  In its native Asia, it survives cold winters well.  Additionally, any storm fronts moving into Maine from the south could carry with it flies from southern states where the winter has not been so harsh.   Thus, berry growers should anticipate needing to manage drosophila for the 2014 season.  Based on our 2012 and 2013 experience, we believe it will be unlikely to significantly infest crops until relatively late in the season when populations reach damaging levels (late August in 2013 at some sites). Therefore, earlier ripening crops such as June-bearing strawberries should not be significantly impacted; but later ripening crops such as fall fruiting raspberries, late ripening varieties of blueberries and fall strawberries will need to be protected as soon as fruit begin to ripen.  We plan to monitor drosophila populations in Maine again in 2014, and carry out research on improving our trapping strategies to provide an early warning system in the future.

Based on what we know so far about this pest, here are six rules for managing spotted wing drosophila.

  1. Monitor for the flies with traps, and for the larvae in fruit.
  2. Spray regularly and often once flies have been found in the field (1-2/week).
  3. Harvest fruit regularly and often; do not leave any ripe/rotten fruit in the field.
  4. Sort fruit at harvest; do not leave any soft fruit in the container to be sold.
  5. Chill all fruit immediately after harvest to 38ºF (or as close as you can) for at least 12 hours to slow development of any eggs or larvae.
  6. Prune the planting to open up the canopy and create dry, light conditions.

Please follow our blog providing regular updates of spotted wing drosophila trapping data and management strategies during the growing season, where you can sign up for notifications of updates.

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Ave
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

 

IPM Web Pages:

http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information.  No endorsement is implied nor is any discrimination intended against other products with similar ingredients.  Always consult product labels for rates, application instructions and safety precautions.  Users of these products assume all associated risks.

Image Description: drosophila trap

Image Description: Spotted Wing Drosophila Trap Captures 2013

Fruit Growers Alert 9/30/13: Spotted Wing Drosophila Counts Remain at High Levels

Fruit Growers Alert – September 30, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

SPOTTED WING DROSOPHILA COUNTS REMAIN AT HIGH LEVELS

We continue to capture spotted wing drosophila flies at all of our monitoring sites from southern, mid-state and coastal Maine. While counts have dropped in some locations over the past week, levels are still high enough to infest any unprotected berries still remaining in the field. Highest counts have been at the coastal sites and lowest counts have been in the more northern and western sites. Our experience has shown that the flies will survive through repeated frosts and continue to infest fruit well into the fall. Therefore, any farms that still have late ripening raspberries, blackberries, blueberries, grapes or day neutral strawberries should continue to protect their crops with an approved insecticide. In some locations a 7-day spray interval may be adequate to prevent infestation, but areas with high fly populations may still require a 4 to 5-day spray schedule.

Recommended insecticide products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®. Effectiveness of these products can range from three to seven days.  Please check product labels for rates, post-harvest intervals and safety precautions.

Four Rules for Managing Spotted Wing Drosophila:

  1. Spray ripening fruit regularly with an approved insecticide (every 5-7 days).
  2. Harvest crop frequently and regularly; remove all ripe and rotten fruit from the field.
  3. Chill all harvested fruit immediately to as close to 33º F as soon as possible; hold in refrigeration until ready to sell.
  4. Open up the planting through pruning and spacing to improve light and air penetration and reduce moisture and humidity within the plant canopy.

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Image Description: Spotted Wing Drosophila Larva in Blackberry

Image Description: Spotted Wing Drosophila Maggot in Raspberry

Fruit Growers Alert 8/30/13: Spotted Wing Drosophila Continues to Spread

Fruit Growers Alert – August 30, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

SPOTTED WING DROSOPHILA CONTINUES TO SPREAD

All sites that we are monitoring in southern and coastal Maine now have spotted wing drosophila flies and fly counts have increased at some sites this week.  We also have more reports from growers of larvae in fruit, indicating that that even low trap captures signal a significant threat.  Spotted wing drosophila (SWD) flies were captured in traps in Wells, Cape Elizabeth, Limington, Springvale, New Gloucester, Gray, Mechanic Falls, Monmouth, Wales, Livermore Falls, Farmington, Oxford, Bowdoinham, Dresden, Warren, Stillwater and Levant.  Trap captures continue to be very variable, ranging from just one fly to nearly 200, with most still catching fewer than 100 per week.  The coastal sites tend to have more flies than any other locations, but counts have been up and down from week to week at many sites. We expect fly populations to rise further in the coming days and weeks.  If you haven’t yet done so, we recommend that growers set up their own traps to monitor for SWD, and learn to distinguish it from other species that will get into the trap.  We recommend that all ripening fruit be protected with an approved insecticide. Regular and repeated treatments are needed to keep fruit from becoming infested. In some locations a 7-day spray interval has not been adequate to prevent infestation, so we have tightened the spray schedule to every 4 to 5 days. Chilling fruit to as close to 32ºF immediately after harvest can significantly reduce the activity and emergence of any larvae.  Keeping the fields clean of over-ripe and rotten fruit can also help reduce the incidence of this insect.

Raspberries before and after infestation, 48 hours at room temperature after picked.

Recommended insecticide products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®.  Effectiveness of these products can range from three to seven days.  Please check product labels for rates, post-harvest intervals and safety precautions.

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Image Description: Fall Raspberries

Image Description: Spotted Wing Drosophila Emerging from Fall Raspberries

Fruit Growers Alert 8/16/13: Spotted Wing Drosophila Spreading, Counts Increasing

Fruit Growers Alert – August 16, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.

SPOTTED WING DROSOPHILA SPREADING, COUNTS INCREASING

Spotted wing drosophila (SWD) flies were captured in traps in Bowdoinham, Cape Elizabeth, Dresden, Gray, Limington, Livermore Falls, Mechanic Falls, Monmouth, New Gloucester, Springvale, Wales, Warren and Wells.  Trap captures varied this week from just one fly to over 100, with most catching fewer than 10.  There are now just a few sites where we haven’t yet caught any flies.   The Bowdoinham site again had far more flies than any other location (135) although this was only about ½ the number we caught at the same location last week. The other sites with higher numbers were Wells (21) and Wales (18).  Some of this variation may just be a matter of where the traps are placed at each site.  Ideally, growers should set up their own traps to monitor for SWD, and learn to distinguish it from other species that will get into the trap.

While there is no valid threshold for spotted wing drosophila in berry fields (most buyers have zero tolerance), growers should initiate a regular insecticide spray program once SWD is captured in your area and you have ripe or nearly ripe fruit in your fields. Recommended insecticide   products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®.  Effectiveness of these products can range from three to seven days.  Repeated applications throughout the harvest season may be required to prevent larvae from infesting the fruit.  Please check product labels for rates, post-harvest intervals and safety precautions. Keeping the fields clean of over-ripe and rotten fruit can also help reduce the incidence of this insect.

David T. Handley
Vegetable & Small Fruit Specialist

Highmoor Farm                       Pest Management Office
P.O. Box 179                             491 College Avenue
Monmouth, ME  04259        Orono, ME  04473
207.933.2100                          1.800.287.0279

IPM Web Pages:
http://extension.umaine.edu/ipm/
http://www.pestwatch.psu.edu/sweet_corn.htm
http://www.umass.edu/umext/ipm/

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

Image Description: Spotted Wing Drosophila Trap

Image Description: Male and Female Spotted Wing Drosophila


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University of Maine Cooperative Extension


Contact Information

Cooperative Extension at Highmoor Farm
52 U.S. Route 202
Monmouth, Maine 04259-0179
Phone: 207.933.2100
The University of Maine
Orono, Maine 04469
207.581.1110
A Member of the University of Maine System