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  • Identifying Symptoms of Mountain Pine Beetle Infestation 


    Check the Needles

    In mountain pine beetle-infested trees, needles start to fade and eventually become rust colored. Fading, which starts in the lower crown and moves upward, generally appears eight to 10 months after the attack.



    Pitch Tubes

    Look for pitch tubes on the lower 15 feet of the tree trunk. These tubes appear as cream- or pinkish-colored masses resembling popcorn.



    Blue Staining

    Use a hatchet to peel back the bark to check the sapwood for blue staining caused by the fungus.




    You may also notice frass (sawdust-looking material) in the cracks of the bark or at the base of the tree.



    Woodpecker Feeding Holes

    Woodpeckers may feed on the MPB larva found underneath the bark. Look for feeding holes one-half to three-quarters of an inch wide along the trunk, along with bark flakes at the base of the tree.