Spotted wing drosophila update- July 8

SWD has been caught in Essex, Elgin, Norfolk, Middlesex, Oxford, Niagara, Halton, Hamilton, & Hastings county.

Cherries and berry crops with ripe fruit are now at risk, and all growers should begin a regular spray program if there is ripe fruit on your farm, including in late June-bearing strawberries, summer-fruiting raspberries, blueberries, and cherries.   

Use as many of these tools as possible through the season to control SWD: 

• Spray every 5-7 days. A list of registered products is below.

SWD prefers moderate temperatures and humid conditions. With temperatures in the mid-20s and rain in the forecast SWD numbers could build up and it is very important to maintain insectide coverage.

• Reapply after ½ inch of rain. For more information on the rainfastness of insecticdes check out this article from John Wise at Michigan State University: https://www.canr.msu.edu/news/rainfast_characteristics_of_insecticides_on_fruit. Note that not all these products are registered in Canada.
  • Using the best products first will help knock the population back down at the beginning of the season. The most efficacious products include Exirel, Delegate, Success, Harvanta and Cormoran.
  • Use products from different groups.
  • Spray in the morning (6-10am) or in the evening (6-10 pm) when SWD is active.
  • Do not spray in temperatures above 25C.
  • Pyrethroid insecticides (Mako, Up-Cyde) will not work well in hot weather and will cause an increase in mites. Save these products for later when weather cools off and mite pressure is low.
  • If possible, choose products that will control other pre-harvest pests as well.

• Keep your fruit picked regularly and clean!
• Cool fruit immediately after harvest.
• Keep alleys clean- either remove unmarketable fruit or crush it in the alley
• After unmarketable fruit is removed it should be destroyed (disposed of, or leave in plastic bags in the sun).
• Make the environment less favourable to SWD- prune the canopy and manage water to reduce humidity (repair leaking drop lines).
• Calibrate your sprayers to ensure excellent coverage once you start to spray.
• Renovate June-bearing strawberries as soon as possible.