Insect Damage to Trees
Bark beetles and balsam wooly adelgids are two insects causing extensive damage to trees across Utah. They can wipe out entire forest stands, as seen in many portions of the Wasatch and Uinta Mountains.
Trees defend themselves by producing sap to deter these insects from laying their eggs below the bark. However, sap production decreases under drought stress, making trees more vulnerable.
During droughts, the reduced sap production makes trees more vulnerable to beetle attacks. Eggs and larval galleries lie just below the bark layer.
The first signs of insect damage include the appearance of brown needles, followed by needle drop and eventually tree death.
Climate changes are leading to warmer winters, resulting in fewer overwintering deaths of these insects. As a result, insect damage is increasing, and forest health is declining.
Click here to read the state’s latest report on insects and disease across Utah’s forests.
Click here to see a video of Dr. Barbara Bentz at Utah State University talking about her research on bark beetles and what inspired her to become a research scientist.
Click here to learn more of Dr. Bentz’s current research.
