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: http://www.omafra.gov.on.ca/english/crops/facts/swd-registrations.htm
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 .
Table 1: Summary of SWD trap captures in Ontario in 2015