Spotted Wing Drosophila Update – June 22 2026

Traps for spotted wing drosophila were placed at a few sites in 2026 – Norfolk, Oxford, and Middlesex.

SWD was identified this week in Norfolk and Middlesex counties. No SWD was found at the other locations.

Trap collected period of:	County/region where SWD was trapped	# of traps with SWD	Total number of SWD trapped this week	# SWD/positive trap
May 20 – May 27	0	0	0	0
May 27 – June 3	0	0	0	0
June 3 – June 10	0	0	0	0
June 10 – June 17	Norfolk, Middlesex	4	6	1.5

Management is needed once we have sustained catch (2 weeks in a row) and ripe fruit is present. These are the first catches of the year, however, we have limited trap locations so monitoring on your own farm is important. If there is ripe fruit present (strawberries, early raspberries, haskaps) use salt water tests to monitor the fruit as an early warning. Watch for soft, juicy fruit.

Pairing a yellow sticky card with a commercial lure for on-farm monitoring is important for timing insecticide applications and effective SWD management.

Trials by Erica Pate and Hannah Fraser in 2025 found that yellow sticky cards work better red sticky cards for catching SWD. It is also easier to see the spots on the male wings (Figure 1) when using yellow cards. For more information about on-farm monitoring see the blog post about the sticky card trial HERE.

Insecticides are needed once SWD is active in your area and there is ripe fruit present. See the table below for a list of registered products. Don’t count on sprays alone:

• Tighten picking schedules- regular, thorough harvest (every 2 days if possible) is important.
• 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 now to ensure excellent coverage once you start to spray.
• Insecticides target SWD adults- make sure to spray when adults are active, in the morning (6am-10am) and evening (6pm-10pm).
• Do not spray in temperatures over 25°C.
• Renovate June-bearing strawberries as soon as harvest is over.