Our next site visit was near Greenleaf to help answer the question on why a resident’s spruce tree was showing signs of failing health. What we found was a single spruce tree next to a barn where it was starving for water, which was making the tree unhealthy. That in turn attracted Spruce Beetles which started their slow death of the tree. Look at 3rd photo below where bark is missing, also notice the 4th photo below of a neighbor’s spruce tree with severe beetle damage. We took a small walk around and noticed several more spruce trees in neighborhood with similar signs of beetle damage.
Signs of beetle damage are where the needles on infested trees may turn a pale yellowish-green color and tend to drop to the ground after high winds, but rarely turn rust colored on the tree. Needles typically drop from branches the second summer after the tree has been infested. Boring dust, produced when beetles bore new entry holes, may accumulate in bark crevices and around the base of the tree. Streams of resin along the main trunk are often associated with recently attacked trees.
What can you do to help protect your spruce tree?
- Maintain the health and vigor of trees: The Spruce Bark Beetle prefers to attack weaker trees or ones that have fallen so maintaining the health and vigor of your trees is important. Tree culturing activities such as watering and fertilizing trees early in the growing season will help develop and maintain healthy trees.
- Prune lower branches to retain a fully crowned tree. Topping mature evergreen trees as illustrated in the pruning link, page 6, sets a tree up for disease and damage: Pruning should be done in the fall and the branches removed from the site if disease is present.
- Spray the tree with an insecticide registered for use on spruce trees to prevent Spruce Beetle attacks: This should be done in spring by early May to protect the tree prior to the beetle’s emergence and dispersal flight.
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| Severe dieback |
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| Spruce tree next to barn |
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| Neighbors tree with severe beetle damage |
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| Noticeable beetle damage |
Spruce beetle impact: from Colorado State forest management
