How Do I Identify a Pine Beetle Infestation?

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  • How Do I Identify a Pine Beetle Infestation?

To identify a pine beetle infestation, you may not see any actual pine beetles, but there are tell-tale signs that a tree has become infested:

Pitch Tubes: Popcorn-shaped globs of sap called pitch tubes will be found on the trunk where the beetle began tunneling. These indicate the tree has tried to “pitch out” the beetle.

Pine beetle infestation - pitch tubes

Pitch tubes indicate a pine beetle infestation.

A red or brown color in the pitch tube indicates a successful attack by the beetle. The color comes from boring dust in the pitch.  A white color indicates an unsuccessful attack – the tree was able to get rid of the beetle before it began boring.  A tree with only a few white tubes has a chance of survival.  If there are several colored tubes present, the tree should be removed.

Pine beetle infestation - red boring dust in the pitch tube

Red boring dust in the pitch tubes from the pine beetles.

Heavy Woodpecker Damage: Evidence of woodpeckers feeding on the trunk may indicate mountain pine beetle infestation in a tree. Signs include patches of bark missing where the woodpecker was feeding and bark flakes on the ground below the tree. Woodpeckers also like to feed on the ips beetle, so be sure to properly identify the beetles you find associated with your tree before deciding on treatment. We can help you make this identification.

Pine beetle infestation - heavy woodpecker damage

Heavy woodpecker damage can also indicate pine beetle infestation

Foliage Color Change: The foliage of trees that have been fatally infested will change color from green to yellow to red.  This color change starts the following spring after the previous summer’s mountain pine beetle flight.  A tree with red needles is beyond the point of saving.

Pine beetle infestation - red needle color

Red needles mean the tree can’t be saved.

Boring Dust: Pine beetles produce a boring dust as they successfully enter into the host tree. You may notice this sawdust-like material in bark crevices or on the ground around the base of the tree. If boring dust is present around the entire base of the tree, the tree is beyond the point of saving.

Pine beetle infestation - boring dust

Boring dust from pine beetles around the base of the tree.

Presence of Live Beetles: You can identify mountain pine beetles throughout their lifecycle by peeling the bark off an infested tree, where you’ll discover eggs, larva, pupae and/or adult beetles underneath.  If you think the tree may be salvageable, don’t do this, as peeling off the bark damages the tree and attracts more beetles to the tree the next year.

Pine beetle infestation - live beetles

Live pine beetles under the bark of an infested tree.

Blue Stain: Pine beetles introduce a fungus as they bore into the tree that stains the sapwood a blue or grey color.

Pine beetle infestation - blue fungus stain

The blue fungus stain from a pine beetle infestation.