Identification

• Adult spruce beetles are small, brown beetles that bore into the wood of the host tree and lay eggs. Most spruce beetles choose dead or dying trees as host trees. However, when there is an extended period of dry weather and an overabundance of dead or dying trees, spruce beetles multiply rapidly. High populations of spruce beetles often begin to attack healthy spruce trees, causing extensive damage and possibly the death of a devastating number of otherwise healthy spruce trees.
  
  

Effects

• Spruce trees under attack from spruce beetles often have a brown or red dust present on the bark of the tree, in cracks on the bark and on the ground beneath the host tree. Spruce tree roots often have small, round entrance holes visible on both underground and exposed roots. Trees infested with spruce beetles are often under attack by woodpeckers removing the tree bark in search of beetles to eat. Spruce trees with high spruce beetle populations typically have yellow or light green needles, instead of healthy dark green needles. After several months, the needles turn red or brown in the summer and drop prematurely.
  
  

Prevention

• Keeping trees healthy is the first step to avoiding spruce beetle infestations. Remove injured, diseased or slow-growing trees to prevent beetle infestations. After removal, spruce tree stumps should be cut as low as possible. Avoid wounding spruce trees or severing their roots, since wounds provide beetles with easy access to the tree. Very old spruce trees should be removed, since spruce beetles commonly infest trees over 150 years old.
  
  

Chemical Controls

• Chemical control products may help prevent spruce beetle devastation if they are applied before infestation occurs. Once spruce beetles have infested the tree, there is little hope of keeping their population low. There are currently no insecticides that can rid spruce trees of this damaging pest once populations are high and heavy damage has occurred.