Neighborhood walk indicates early season damage
May 4, 2007 - Author: Dave Smitley, Michigan State University Extension, Department of Entomology
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.
On a walk around an East Lansing neighborhood at the beginning of the week, I was on the lookout for tree and shrub problems. It is early for most insects, but I could still find signs of insect injury from last year, and plenty of winter injury. I had only walked a block before I found the first dead birch tree. It was a European white birch that had grown to a height of about 20 feet before dying from bronze birch borer attack. We now know that native paper birch (Betula papyrifera) are completely resistant to bronze birch borer, while European and Asian species are susceptible and must be treated each spring with an imidacloprid basal soil injection or basal drench.
In several places on the nearby MSU campus, I saw lots of dead shoots on yews. On closer inspection, I could see that every dead shoot originated close to a pruning wound from last fall where a branch was removed. Apparently the pruned branch made these now dead shoots more susceptible to winter injury. The last thing I noticed was the salt injury to a variety of trees and shrubs located close to the road. In this case, juniper foliage closest to the curb died, while the rest of the shrub survived. In some places I saw white pine foliage turning brown on the side facing the road even when the trees were 30 feet or more away from a high-speed road where the salty water splashed and drifted a long ways.