Forestry insect update
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
The new Pales weevil adults are emerging. Typically they emerge now through mid-September. They spend the day in the litter around the trees and move onto trees at night to feed on shoots and twigs. Eventually, they seek a site to overwinter, usually in litter below the tree, and emerge in the spring to start the cycle again. We have seen feeding at this time of the year causing flagged shoots on Douglas fir and white pine. Look for small irregular patches of exposed wood on seedling stems or at the base of flagged shoots. If you have had a problem with pales weevil, now is the time to apply a registered insecticide to trees to control these adults as they move into the trees to feed on shoots.
We will sometimes see mite populations build again this time of the year. Pay particular attention to the trees you plan to harvest this year. Check for mite activity by closely inspecting the older needles near the tree stem or by sharply rapping shoots over white cardboard or a notebook with white paper. Immature mites will be pinkish in color while adults are dark green or brownish.