Blue Spruce Diseases Colorado blue spruce is a popular tree species planted for windbreaks, screens and general landscape purposes. Unfortunately, blue spruce is susceptible to several diseases and insect pests. To learn more about these diseases and how to control them view the Spruce Problems handout prepared by the Conservation District.
Diplodia Tip Blight The fungus Diplodia pinea can cause serious damage to Austrian, ponderosa, red, Scots, mugo, jack, and white pine. For more information go here:
Forest Tent Caterpillar The forest tent caterpillar is a native species found throughout hardwood forests of North America. It feeds on the leaves of many trees, but in Michigan outbreaks occur in aspen, birch, basswood, sugar maple and oak stands. More information is available here:
Hemlock Woolly Adelgid The Hemlock Woolly Adelgid has been discovered in several Michigan locations and the Department of Agriculture and Rural Development has instituted a quarantine related to this pest.
Oak Wilt This is an aggressive disease that affects many species of oak. It is one of the most serious tree diseases in the eastern United States, killing thousands of oaks each year in forests, woodlots, and home landscapes. Learn more about Oak Wilt at:
Spruce Decline, Diseases & Pests Spruce trees are experiencing decline throughout Michigan from a variety of maladies—including several needle cast and canker diseases; gall aphids and spider mites. To learn more about what may be affecting your spruce trees, view the Spruce Problems handout prepared by the Conservation District.
Thousand Cankers Disease This disease has the potential in impact black walnut trees in Michigan.