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: http://www.omafra.gov.on.ca/english/crops/facts/swd-registrations.htm.
Update to the update: 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.