Preventative treatment must be applied prior to the bark beetles' first flight in spring, or host tree attack if later in the year. If applying preventative treatments after beetles have become active, the tree must be inspected prior to treatment to ensure that it is not colonized. Highly stressed trees may not produce pitch tubes. Outward signs of colonization may not be visible from the ground either. In these cases, it may be best to hire a climber to inspect the tree to ensure the tree does not have bark beetles in it. Once the bark beetles have entered the tree, no products are scientifically proven to be effective at controlling them.
Jeff Schalau, Associate Agent, University of Arizona, and Tom DeGomez, Area Agent and Regional Specialist, University of Arizona
