- SWD numbers continue to increase! Pressure from this insect is very high now.
- Use all forms of management- weekly sprays, regular, thorough harvest (every 2 days or less) and immediate post-harvest cooling to less than 5 C (preferably cooler).
- SWD is present at almost all of our monitored sites, including Grey County and eastern Ontario to Ottawa.
- Use the salt water test to look for SWD in fruit.
- Pyrethroid insecticides (MAKO) will not work well in hot weather and will cause in increase in mites. Save the use of this product for later – when weather cools off and mite pressure is low.
- Two spotted spider mite is also a problem in many strawberry and raspberry fields – SWD sprays are hard on predators (especially pyrethroids) so monitor your fields for mites.
- Blueberry growers – if you can’t spray your whole field, at least consider spraying outside rows
- Heavy rains will reduce insecticide residue. Re-application is needed after ½-inch rains.
- If you can’t keep up with harvest in day neutral strawberries consider removing older blocks.
- If severe infestation occurs, strip ripening fruit from infested blocks of raspberries and day-neutral strawberries, spray and start again.
- In fall-bearing raspberries, bees and pollinators are abundant right now. Protect pollinators by choosing least toxic options and spraying at night.
- Hot, humid conditions can lead to spray burn. Make sure temps have cooled off below 25 C before you spray.
Table: Summary of Spotted Wing Drosophila (SWD) Trap Captures
Week traps collected |
# sites with SWD/# sites checked |
# SWD trapped |
Ave # SWD/trap |
Counties where SWD was found |
Crops where SWD was trapped |
May 29 – June 4 |
0/7 |
0 |
0 |
_ |
_ |
June 5 – June 11 |
2/16 |
2 |
1.0 |
Essex, Niagara |
wild hosts |
June 12 – June 18 |
3/24 |
3 |
1.0 |
Kent, Elgin, Niagara |
wild hosts, strawberries |
June 19 – June 25 |
3/25 |
3 |
1.0 |
Essex, Middlesex |
wild hosts, raspberries |
June 26 – July 2 |
4/30 |
11 |
1.6 |
Essex, Kent, Brant, Elgin |
wild hosts, strawberries, raspberries |
July 3 – July 9
|
9/29 |
27 |
1.8 |
Essex, Kent, Elgin, Middlesex, Norfolk, Oxford, Waterloo, Niagara |
wild hosts, raspberries, peaches, cherries |
Jul 10 – Jul 16
|
30/30 |
136 |
4.7 |
Essex, Kent, Elgin, Middlesex, Norfolk, Brant, Oxford, Haldimand, Niagara, Durham |
Wild hosts, blueberries, blackberries, raspberries, strawberries, peaches, cherries |
July 17-23
|
30/30 |
1,757 |
31.4 |
Essex, Kent, Elgin, Middlesex, Norfolk, Brant, Oxford, Haldimand, Niagara, Wellington, Peterborough, Northumberland, Grey Stormont, Dundas and Glengarry |
Wild hosts, blueberries, blackberries, raspberries, strawberries, peaches, cherries, saskatoons, plums, pears |
July 24-July 31
|
27/29 |
4,147 |
59.2
|
Essex, Kent, Elgin, Middlesex, Norfolk, Brant, Oxford, Haldimand, Niagara, Wellington, Peterborough, Northumberland, Grey , Stormont, Dundas and Glengarry |
Wild hosts, blueberries, blackberries, raspberries, strawberries, peaches, cherries, saskatoons, plums, pears |
August 1 – 6 |
29/29 |
6,800 |
80 |
Essex, Kent, Elgin, Middlesex, Norfolk, Brant, Oxford, Haldimand, Niagara, Wellington, Peterborough, Northumberland, Grey , Stormont, Dundas and Glengarry |
Wild hosts, blueberries, blackberries, raspberries, strawberries, peaches, cherries, saskatoons, plums, pears |
August 7 – 13* (Data incomplete at this time) |
17/29 |
17,346 |
309.8 |
0 comments on “Spotted Wing Drosophila (SWD) update August 11, 2016”