Signs and Symptoms
Know how to identify a pine tree infested with mountain pine beetles
Fall is an ideal time for residents to check for the presence of mountain pine beetles in their pine trees, especially lodgepole, ponderosa and limber pines. Each year, these beetles take flight in late summer to look for new host trees. By fall, enough time has passed to see signs of infestation, but the weather is often warm and dry enough for outdoor walks.
Residents should look for these tell-tale signs and symptoms of mountain pine beetle infestation:
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Popcorn-shaped masses of resin, called pitch tubes, on the trunk that may be brown, pink or white
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Boring dust in bark crevices and on the ground immediately adjacent to the tree’s base
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Woodpecker damage, where the birds have stripped portions of the bark in search of larvae, leaving accumulations of bark at the base of the tree
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Presence of live mountain pine beetles (eggs, larvae, pupae and/or adults)
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Exit holes on the bark’s surface where adult beetles have emerged
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Foliage turning yellowish to reddish throughout the entire tree crown, which usually occurs eight to 10 months after a successful attack
