Too late to spray newly hatched eggs; now wait till buds open
I checked my monitored winter moth eggs in Kingston this morning. Most eggs have hatched. I don’t think it makes sense to try and spray for winter moth this week unless your fruit trees and blueberries are right near the ocean. The next chance to spray apples, pears, and blueberries will be in a couple of weeks (or longer if cool temperatures continue) when buds open up a bit and caterpillars are climbing around. When caterpillars are inside closed buds like they are now, insecticides can’t reach them.
What are cold temperatures going to do to winter moth caterpillars? I’m afraid caterpillars will survive better than flower buds. I will check bud survival and caterpillar survival at the end of this week.
Now is not the time to spray landscape trees. Wait for leaf buds to open and new leaves emerge.