Surveys have shown that we are making progress in reducing the numbers of this very serious pest of apples. However, it is very important to continue the trunk sprays to keep populations below damaging levels.
The adults have been emerging and larvae will be starting to hatch this week. The control measures are timed to kill them . At the end of this week (July 15-17th), apply a trunk spray . It would be a good idea to make a second application in about ten days. If you are concerned that your levels are still very high, do an additional one in another ten days.
Control the vegetation around the trunk before you spray so that you can get adequate coverage.
Irrigate just before you spray so that you will have the maximum time possible before it is time to irrigate again.
Use a gun spray to get good coverage. Apply enough volume of spray that some of it will run into the cracks and crevices where the larvae take refuge. Air blast and weed sprayer type of applications have been shown to be far less effective.
Entrust is still the only product registered for this insect. The rate for Entrust is 75 grams of product/ha in up to 1,500 litres of water/ha. There are two other products – Rimon and Delegate – that submissions are in for registration for control of clearwing moth. However, as of today, they have not been approved.
If you have any questions phone Linda Edwards at 499-5303