2015 Ontario Trap Catches: Spotted Wing Drosophila

Table of Contents

  1. SWD monitoring map - results from trap collections
  2. Current update for Ontario
  3. SWD life stage predictions according to degree day model
  4. SWD project for 2015
  5. SWD historical data
  6. Links to weekly updates in other regions

This project was made possible by the Ontario Berry Growers Association and the Ontario Highbush Blueberry Growers Association. Funding assistance to the OBGA was provided by Dow AgroSciences Canada, Engage Agro Corp., Bayer CropSciences Inc. and E.I. du Pont Canada Company. We are grateful for the continued support of the HJ Heinz Co. for the apple cider vinegar used as bait in our traps.

This project was also funded in part through Growing Forward 2, a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists in the delivery of Growing Forward 2 in Ontario.

SWD monitoring map - results from trap collections

Figure 1: Map showing SWD trap captures each week by county in 2015. Watch the map as it scrolls through the weeks.

SWD monitoring map - results from trap collections

Current updates for Ontario

August 14 - Spotted wing drosophila trap captures continue to escalate. Trap captures increased 150% this past week and 400% the week before. SWD flies are abundant and are seeking ripening fruit to lay eggs. Our students are picking up infested raspberries and blueberries in both eastern and southern Ontario (we are not collecting information in northern Ontario).

All ripe and ripening tender fruit and berry crops are susceptible at this time. Fall bearing raspberries, day neutral strawberries and late season blueberries require weekly control. Use salt tests to decide if your control program is adequate. Using salt tests we have noticed dramatic increases in larvae numbers in raspberries. SWD causes fruit quality problems. If your fruit is soft, leaking juice or collapsing a day or two after harvest, your customers won't come back for more.

Do not take chances with SWD control right now. Minimize the amount of fruit that is left in the field by picking early, clean and often. Refrigerate fruit immediately after harvest to slow pest development in the fruit.

Updated: Insecticide recommendations for all fruit crops can be found at: www.ontario.ca/spottedwing. Since these recommendations were published, Delegate has been fully registered on peaches and nectarines for SWD with a 1 day phi, when used for this pest.

Table 1: Summary of SWD trap captures in Ontario in 2015
Trap collected week of: # sites positive for SWD Counties /crops where SWD was trapped # of traps with SWD Total # SWD trapped this week # SWD/positive trap
June 1-6
1
Norfolk
1
3
3
June 7-13
3
Halton, Durham, Oxford
3
3
1
June 14-20
2
Essex,Niagara
2
2
1
June 21-27
5
Norfolk, Oxford, Niagara, Kent, Quinte West
6
6
1
June 28-July 4
9
Norfolk, Oxford, Niagara, Brant, Elgin, Halton
11
14
1.3
July 5-11
14
Essex, Kent, Elgin, Middlesex, Oxford, Norfolk, Brant, Haldimand, Niagara, Halton, Carleton, Stormont
17
84
4.9
July 12-18
28
All of the above plus Lambton, Wellington, Grey, Durham region, Prince Edward, Quinte West

61

445
7.3
July 19-25
32
Kawartha Lakes region is new this week
78
896
11.0
July 26 - August 1
31
All monitored sites are positive. SWD is present in all areas.
86
2,515
29.4
Aug 2-8
31
All monitored sites are positive. SWD is present in all areas.
103
10,718
104
August 9-15
30+
All monitored sites are positive. SWD is present in all areas.
104+
18,044+
173

Chart showing SWD activity in Ontario showing dramatic increases over the growing season

chart showing SWD activity in Ontario - number of insects per trap increasing dramatically

SWD life stage predictions according to degree day model August 14

SWD development has been related to temperatures (degree days) by researchers in Oregon. We used their model, and weather data from Environment Canada, to see how it predicted SWD population development in Ontario. Reference: Online Pheonology and Degree-day Models.

SWD populations are most advanced in Essex county, where third generation adults are now emerging and peak egg laying by this generation is expected next week.

Otherwise, in most of Ontario, this is a peak time for egg laying by second generation SWD. Third generation SWD emergence will peak next week.

In the cooler regions ( Kingston, Coburg) 2nd generation SWD is still predominant. It is important to remember that although pest pressure is not as extreme in these cooler regions it is still high!

The take home message is : this is an important time for SWD control everywhere in Ontario .

All degree days calculated in Celsius, base 10. You can calculate the degree days in your area to see how your location compares to the ones on the chart below.

This data was compiled by Abbie Wiesner, OMAFRA Vineland

Location Current stage of SWD
August 15, 2015
Accumulated
Degree days
Next event forecast
Harrow August 9th = 977.7
Peak adult emergence 3rd generation adults
1034.1
August 19th = ~1104.4
Peak egg laying by 3rd generation females
London August 5th = 833.8
Peak egg laying by 2nd generation females
906.1
August 19th= ~969.4
Peak adult emergence 3rd generation
Delhi August 4th = 829.7
Peak egg laying by 2nd generation females
910.1
August 19th= ~978.7
Peak adult emergence 3rd generation
Waterloo August 9th = 832.4
Peak egg laying by 2nd generation females
867.3
August 22nd = ~969.0
Peak adult emergence 3rd generation
Hamilton August 6th = 832.7
Peak egg laying by 2nd generation females
895.2
August 19th= ~970.4
Peak adult emergence 3rd generation
Vineland Station August 7th = 829.1
Peak egg laying by 2nd generation females
884.9
August 21st = ~970.4
Peak adult emergence 3rd generation
Niagara on the Lake August 8th =973.1
Peak adult emergence 3rd generation adults
1017.3
August 21st = ~1109.6
Peak egg laying by 3rd generation females
Whitby August 4th = 836.6
Peak egg laying by 2nd generation females
930.5
August 17th= ~973.0
Peak adult emergence 3rd generation
Trenton August 7th = 833.1
Peak egg laying by 2nd generation females
903.9
August 19th= ~969.5
Peak adult emergence 3rd generation
Cobourg August 3rd = 553.8
Peak egg laying by 1st generation females
651.9
August 18th= ~705.2
Peak adult emergence 2nd generation
Kingston August 2nd = 702.9
Peak adult emergence 2nd generation
818.4
August 15th = ~830.9
Peak egg laying by 2nd generation females
Ottawa August 2nd =834.3
Peak egg laying by 2nd generation females
936.5
August 17th= ~979.2
Peak adult emergence 3rd generation

July 31 - Spotted wing drosophila trap captures continue to escalate. Second generation females are now active in most areas. Using a degree day model developed in Oregon, (which has not been validated in Ontario), we expect a lot of SWD egg laying in the first week of August. All berry crops should be protected from SWD at this time.

Do not take chances with SWD control right now. The next 5-6 weeks are critical for keeping things under control. Minimize the amount of fruit that is left in the field by picking early, clean and often.

  • SWD is present at 100% of the monitored sites .
  • We are trapping SWD in eastern and northern regions as well as southern Ontario. These areas are about a week behind the earliest regions but are also at risk where ripe fruit is present.
  • The biggest increases are in wild hosts, strawberries, raspberries and unsprayed stone fruit such as apricots. This means that SWD are multiplying in these crops.
  • Damage has been found in strawberries, raspberries, black raspberries, cherries, saskatoons, and is likely in blueberries.
  • All growers should do salt water immersion tests to determine if SWD is building up in their crops.
  • Summer red raspberries: Apply weekly insecticides. Harvest as thoroughly as possible every 2 days. This is difficult given the big crop but it is at risk in all areas!
  • Fall-bearing raspberries: Strip ripening fruit off the lower parts of the plant until there is enough fruit to harvest every 2 days. Begin a regular insecticide program as primocane fruits begin to ripen. Do not let SWD build up on the small crop that develops early at the base of the plant.
  • Blackberries: Where fruit is ripening, begin an aggressive insecticide program and harvest as thoroughly and as often as possible.
  • Blueberries: Harvest is in progress and fruit is susceptible. Apply a preharvest insecticide to blocks of late varieties green fruit, choosing an insecticide which will also control Japanese beetle. Apply insecticides weekly once fruit begins to ripen. Do not skip these early insecticides, which are critical to keeping populations under control.
  • Day neutral strawberries: Ripe fruit is susceptible now. Harvest thoroughly every 2 days. Begin an insecticide program now that fruit has become abundant.
  • June bearing strawberries: Unharvested fruit is now a source of SWD. Mow and renovate as soon as possible. Apply a post harvest insecticide to blocks adjacent to raspberries or blueberries.
  • Peach, plum, and tender fruit growers should choose insecticides for oriental fruit moth that also control SWD.
  • All berries and stone fruit crops: Do salt water assessments and close observation to check for SWD damage. Juice leaking from fruit indicates a serious problem. Keep fruit in a cooler, as soon as possible after harvest.

UPDATED: Insecticide recommendations for all fruit crops can be found at: www.ontario.ca/spottedwing

July 24 - Spotted wing drosophila trap captures continue to escalate indicating that they have completed a generation or two in susceptible crops. Do not take chances with SWD control right now. The next 5-6 weeks are critical for keeping things under control. Minimize the amount of fruit that is left in the field by picking early, clean and often.

  • SWD is present at 90% of the monitored sites .
  • We are trapping SWD in eastern and northern regions as well as southern Ontario. These areas are about a week behind the earliest regions but are also at risk where ripe fruit is present.
  • The biggest increases are in wild hosts, strawberries, raspberries and unsprayed stone fruit such as apricots. This means that SWD are multiplying in these crops.
  • Damage has been found in strawberries, raspberries, black raspberries and saskatoons, and is likely in blueberries.
  • All growers should do salt water immersion tests to determine if SWD is building up in their crops.
  • Summer red raspberries: Apply weekly insecticides. Harvest as thoroughly as possible every 2 days. This is difficult given the big crop but it is at risk in all areas!
  • Fall-bearing raspberries: Strip ripening fruit off the lower parts of the plant until there is enough fruit to harvest every 2 days. Begin a regular insecticide program as primocane fruits begin to ripen. Do not let SWD build up on the small crop that develops early at the base of the plant.
  • Blackberries: Where fruit is ripening, begin an aggressive insecticide program and harvest as thoroughly and as often as possible.
  • Blueberries: Harvest is in progress and fruit is susceptible. Apply a preharvest insecticide to blocks of late varieties green fruit, choosing an insecticide which will also control Japanese beetle. Apply insecticides weekly once fruit begins to ripen. Do not skip these early insecticides, which are critical to keeping populations under control.
  • Day neutral strawberries: Ripe fruit is susceptible now. Harvest thoroughly every 2 days. Begin an insecticide program when fruit becomes abundant.
  • June bearing strawberries: Unharvested fruit is now a source of SWD. Mow and renovate as soon as possible. Apply a post harvest insecticide to blocks adjacent to raspberries or blueberries.
  • Peach, plum, and tender fruit growers should choose insecticides for oriental fruit moth that also control SWD.
  • All berries and stone fruit crops: Do salt water assessments and close observation to check for SWD damage. Juice leaking from fruit indicates a serious problem. Keep fruit in a cooler, as soon as possible after harvest.

UPDATED: Insecticide recommendations for all fruit crops can be found at: www.ontario.ca/spottedwing

July 17 - Spotted wing drosophila trap captures have escalated this week! Do not take chances with SWD control right now.

  • SWD was present at 50% of the monitored sites last week and is approaching 80% of sites this week. Traps are not 100% efficient for individual sites, so we use regional trednds to predict activity.
  • The number of flies per positive trap has increased dramatically, especially in southern Ontario, were 2-3 generations are completed.
  • The biggest increases are in wild hosts, strawberries, raspberries and unsprayed stone fruit such as apricots. This means that SWD are multiplying in these crops.
  • We have trapped SWD in eastern Ontario as well. Numbers are lower, but berry crops in eastern Ontario are also at risk.

Summer red raspberries: Apply weekly insecticides. Harvest as thoroughly as possible every 2 days. This is difficult given the big crop but it is at risk in all areas!

Fall-bearing raspberries: Strip ripening fruit off the lower parts of the plant until there is enough fruit to harvest every 2 days. Begin a regular insecticide program as primocane fruits begin to ripen. Do not let SWD build up on the small crop that develops early at the base of the plant.

Blackberries: Where fruit is ripening, begin an aggressive insecticide program and harvest as thoroughly and as often as possible.

Blueberries: Harvest is in progress and fruit is susceptible. Apply a preharvest insecticide to blocks of late varieties green fruit, choosing an insecticide which will also control Japanese beetle. Apply insecticides weekly once fruit begins to ripen. Do not skip these early insecticides, which are critical to keeping populations under control.

Day neutral strawberries: Ripe fruit is susceptible now. Harvest thoroughly every 2 days. Begin an insecticide program when fruit becomes abundant.

June bearing strawberries: Unharvested fruit is now a source of SWD. Mow and renovate as soon as possible. Apply a post harvest insecticide to blocks adjacent to raspberries or blueberries..

Cherry and tender fruit growers should choose insecticides for cherry fruit fly or oriental fruit moth that also control SWD.

All berries and stone fruit crops: Do salt water assessments and close observation to check for SWD damage. Juice leaking from fruit indicates a serious problem. Keep fruit in a cooler, as soon as possible after harvest.

Insecticide recommendations for all fruit crops can be found at ontario.ca/spottedwing

In addition to the list at this link, Entrust and Success are now fully registered for SWD on berry crops We will update our on-line information to reflect this as soon as possible.

July 10 - Spotted wing drosophila trap catches continue, predominantly in southern Ontario. In recent weeks we trapped SWD in Essex, Kent, Elgin, Norfolk, Oxford, Middlesex, Brant, Haldimand, Niagara, Halton, as well as the eastern Ontario counties of Quinte west and Carlton. Numbers are starting to increase in earliest areas. So far most of or trap catches are in wild hosts, often near strawberries, but we have also found them in raspberries, blueberries and cherries. Wild fruit is now ripe and will contribute to the buildup of SWD in the environment. SWD have been reared from strawberry and raspberry fruit collected June 23, indicating that in southern Ontario, flies were actively laying eggs in ripe fruit before that date.

Moderately warm and humid conditions are perfect for SWD. All ripe and nearly ripe fruit is at risk for infection. Raspberries, cherries and early blueberries are at risk. Watch for unusually soft and leaky fruit. Berry growers who buy fruit from other growers should make sure these suppliers have SWD under control.

Raspberry growers should have all aspects of a management plan in place, including early and frequent harvest, and regular application of insecticides with a well calibrated sprayer. Best options at this time include Delegate, Entrust, Success, Malathion. Of these, all will control small caterpillars and loopers, but only malathion will control rose chafer. Rotate products from different families as much as possible.

Blueberry growers should consider pre-harvest insecticides where berries are blue. Options for blueberries include Delegate, Entrust, Success, Malathion, Imidan and Exirel. Imidan has a long phi so is not that useful for SWD but also controls Japanese beetle.

Cherry growers should choose an insecticide for cherry fruit fly that also controls SWD.

Insecticide recommendations for all fruit crops can be found at ontario.ca/spottedwing

In addition to the list at this link, Entrust and Success are now fully registered for SWD on berry crops We will update our on-line information to reflect this as soon as possible.

July 7 - Spotted wing drosophila trap catches continue, predominantly in southern Ontario. Numbers are starting to increase in earliest areas. Wild fruit is now ripe and will contribute to the buildup of SWD in the environment. SWD have been reared from strawberry and raspberry fruit collected June 23, indicating that in southern Ontario, flies were actively laying eggs in ripe fruit before that date.

Raspberry growers should have all aspects of a management plan in place, including early and frequent harvest, and regular application of insecticides with a well calibrated sprayer. Best options at this time include Delegate, Entrust, Success, Malathion. Of these, all will control small caterpillars and loopers, but only malathion will control rose chafer.

Blueberry growers should consider pre-harvest insecticides where berries are blue.

Moderately warm and humid conditions are perfect for SWD. All ripe and nearly ripe fruit is at risk for infection. Raspberries, cherries and early blueberries are at risk.

Insecticide recommendations for all fruit crops can be found at ontario.ca/spottedwing.

Entrust and Success were fully registered for SWD on berry crops last week, and we will update our on-line information to reflect this as soon as possible .

June 26 - SWD are being trapped now, mostly in southwestern Ontario. Growers with raspberries ripening in southwestern Ontario should spray for SWD before harvest begins. Best options at this time include Delegate, Entrust, Success, and Malathion. Of these, all will control small caterpillars and loopers, but only Malathion will control rose chafer.

Strawberries are also at risk of SWD infestation in these areas, but with harvest in progress, the need to spray is less certain. Continue to watch for damage excessively soft or leaky fruit. Growers with large blocks of late season varieties, or producing blocks of day neutral varieties could spray an insecticide, especially if there is an abundance of overripe fruit on early varieties nearby. It is better to just pick early, clean and often. So far we continue to catch SWD flies only here and there. We have not caught them in the same trap twice, and have seldom trapped them at the same site twice. Degree day models suggest that emergence of the first generation SWD adults is peaking now or next week across most of Ontario. These SWD will be looking for ripe fruit to lay eggs in the next week or two.

Sweet cherries are also at risk. A preharvest insecticide for SWD can prevent larva in the fruit at harvest. Sour cherry growers should choose a spray for cherry fruit fly that also controls spotted wing drosophila

Insecticide recommendations for all fruit crops can be found at ontario.ca/spottedwing

Entrust and Success were fully registered for SWD on berry crops last week, and we will update our on-line information to reflect this as soon as possible.

June 16 - Spotted wing drosophila adults are active already. We have found low numbers of flies at sites in Essex, Norfolk Oxford, and Halton counties and Niagara and Durham region. This is about three weeks earlier than normal.

Degree day models for southern Ontario suggest that the overwintering generation of SWD is laying eggs in fruit. In earliest areas, the model predicts that the first generation of flies is beginning to emerge from infested fruit. Since the only fruit present right now is strawberries and haskaps, these crops are theoretically at risk. We do not normally see damage on strawberries and haskaps until after the June harvest is over, so I am reluctant to suggest special sprays for SWD at this time. However, watch closely for signs of premature breakdown and poor quality of these crops. (Figure 1) . Keep all ripe fruit harvested on a tight schedule, and refrigerate as soon as possible after harvest. If possible, remove unmarketable fruit from the field.

Products registered for spotted wing drosophila control on berry crops include Malathion and Delegate. Mako, formerly named Ripcord, is registered on strawberries and raspberries but not blueberries and is labelled for "suppression only" for SWD. See www.ontario.ca/spottedwing for current registrations.

Exirel is fully registered on blueberries and other bushberries for SWD control. Bushberries include haskaps, saskatoons, sea buckthorn, currants and blueberries.

Figure 1: SWD damage on strawberry- soft or bruised appearance on on side

Figure 1: SWD damage on strawberry- soft or bruised appearance on on side

June 5 - A regional monitoring program for Spotted Wing Drosophila is being coordinated by Erin Hanna, OBGA, and OMAFRA. SWD traps for adult flies will be set up at 30 sites across Ontario, starting in early June. .

For the week of June 1-5, samples were collected from 51 traps at 15 locations across Ontario. To our surprise, SWD was collected from one site in Norfolk County. Next week's counts will tell us if SWD is unusually active or if this early capture is just random. Usually we see the first SWD in late June and early July. However, the degree-day model suggests that the first overwintering SWD will be laying eggs now.

If we continue to catch SWD in our traps next week, we will recommend that growers consider protecting susceptible crops such as Haskaps and day-neutral strawberries.

Information on SWD activity in Ontario will be updated weekly in the Berry Bulletin, Hort Matters newsletter, ONFruit blog, and on our website.

Jim Chaput and the minor use coordinators have secured emergency use registrations for SWD in 2015. These include:

  • MAKO, formerly known as Ripcord. Registered for one application on strawberries, raspberries, but not blueberries, also stone fruit and grapes.
  • Delegate on all berry crops, stone fruit and grapes
  • Malathion 85 E on all berry crops, stone fruit and grapes.

Two products are also fully registered for SWD:

  • Exirel for blueberries
  • Imidan, on blueberries (but it has a 14 days to harvest interval (PHI) .)
  • Delegate on berry crops

Details will be posted soon.

Spotted wing drosophila project for 2015

After 4 years of monitoring for Spotted Wing Drosophila (SWD) at 50-100 sites each year in Ontario, we think this pest is here to stay. Every year we capture the first SWD flies in late June or early July, around the end of June strawberry harvest and the time of summer raspberry harvest. Every year the trap captures quickly escalate, with SWD pressure being extremely high during blueberry and fall raspberry harvest. We have consistently found damage in all the berry crops except early strawberries, and suspect cherries have been damaged as well. Our message to growers is to protect susceptible soft fruit crops if they are ripening when SWD flies are active.

However, we have noticed that trap captures on individual farms do not predict the potential for crop damage on that same farm. We sometimes find damage before SWD are caught in traps at that site. We think it is more useful to consider trap captures in an area, rather than an individual farm. We also think that growers should focus their efforts on recognizing the first signs of damage to fruit. Immersing fruit in salt water to float out SWD larvae is also a good tool for growers to assess their SWD management programs.

To support berry growers in their management of SWD, the Ontario Berry Growers Association (OBGA) and OMAFRA have teamed up to run a regional SWD monitoring program in 2015. The project will be coordinated by Erin Hanna, who works for the OBGA. Traps will be placed at approx. 30 representative sites across the province, from Harrow to Georgian Bay to Ottawa. Volunteers from agribusiness, private consultants and OMAFRA students will pick up the traps and send them to Vineland, where OMAFRA students will process the trap contents. Weekly reports on SWD activity will be sent to berry growers through the Berry Bulletin, and available to all growers on onfruit.wordpress.com/ as well as in Hort Matters newsletter.

Table 1: Regional monitoring locations for SWD traps in 2015
County
# of sites
Site locations
Essex
4
Harrow, Cottam
Kent
2
Thamesville, Blenheim
Lambton
1
Arkona
Huron
1
Bayfield
Grey
1
Clarksburg
Elgin
2
Port Burwell, Aylmer
Middlesex
1
London
Oxford
1
Woodstock
Brant
1
Scotland
Norfolk
2
Simcoe
Haldimand
1
Dunnville
Niagara
5
Vineland, St. Catharines, Fenwick, Jordan
Wellington
1
Puslinch
Halton
1
Milton
Durham
2
Bowmanville, Newcastle
Prince Edward
1
Picton
Kawartha Lakes
1
Buckhorn
Northumberland
1
Brighton
Quinte West
1
Wooler
Stormont
1
Avonmore
Ottawa/Carleton
1
Richmond

SWD flies trapped in Ontario, by region, 2014

Figure 1: SWD flies trapped in Ontario, by region, 2014. (text version)

Pattern of SWD fruit infestation in Ontario in 2014. Marketable fruit was collected and held at room temperature until SWD flies emerged.

Figure 2: Pattern of SWD fruit infestation in Ontario in 2014. Marketable fruit was collected and held at room temperature until SWD flies emerged. (text version)


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca