Tree problems · Insect
Mountain pine beetle: signs and what to do
Mountain pine beetle is an insect pest, often seen on ponderosa pine, lodgepole pine, limber pine. Look for: small, popcorn-shaped lumps of pitch (pitch tubes) on the trunk where beetles tried to enter.
General information, not a diagnosis. A certified arborist or your county extension office can confirm.
- Insect
- Ponderosa pine
- Lodgepole pine
- Limber pine
- Whitebark pine
Signs to look for
Tick what you see. More ticks make it more likely, but only an on-site look can confirm.
0 of 6 signs ticked. Ticks stay in this browser only.
Season
Adult beetles fly and attack in summer. Needles usually turn red months later, so a tree can look healthy after it has already been attacked.
How it spreads
Beetles fly from tree to tree on their own. When many beetles are present, they can overcome even healthy pines. Moving fresh pine logs and firewood can carry beetles to new spots.
Where it is found
Mountain pine beetle is a native bark beetle of western pine forests, and it has caused large outbreaks in western North America. Check your state official map; ranges change.
Official sources
What to do
- 1
Look for pitch tubes and boring dust on the trunk, not only at the needles.
- 2
Do not wait for red needles. By then the beetles have usually already left the tree.
- 3
Call a certified arborist or your state forestry office to confirm the cause.
- 4
A tree that is fully colonized cannot be saved. Removing it can lower the risk of a falling dead tree and can help nearby pines.
- 5
Ask a licensed applicator about preventive treatment for high-value pines nearby. It must be done before beetles attack, and label rules apply.
Safety first: do not climb, do not cut near power lines and do not use a chainsaw on storm-loaded wood. Call the utility for downed lines and 911 if anyone is in danger.
Prevention
Keep pines healthy: water deeply in dry spells, avoid soil compaction and root damage, and do not wound trunks. Thinning crowded stands makes trees stronger, and extension and Forest Service guidance supports it. Do not stack fresh pine logs or firewood next to living pines.
When to call a pro
Call a certified arborist as soon as you see pitch tubes or boring dust, or if a pine near your home is fading. Dead pines can fall without warning, so call right away if one is near a house, driveway or power line.
Not sure who to call? Read how to hire a tree service or check is my tree dangerous?
Trees it affects
Usually seen on: Ponderosa pine, Lodgepole pine, Limber pine, Whitebark pine.
See all species in our tree library, or pick a tougher tree with the tree picker.
For tree companies
How to explain mountain pine beetle to a customer
Explain that this beetle is a natural part of western forests, but outbreaks hit stressed and crowded trees hardest. Tell the owner plainly that a fully attacked tree cannot be saved, and that preventive treatment only works before the attack and is not a guarantee. Offer a written inspection, then let the owner decide.
Send this page to the customer after your visit so they can read the signs in plain words. See also selling plant health care and the job photo checklist.
Questions
Can a pine with mountain pine beetle be saved?
Not once the beetles have fully colonized it. Preventive protection of nearby healthy, high-value pines may be possible before an attack. A certified arborist can tell you which case you have.
Why are the needles red but the tree was green last month?
Needles often stay green for months after the beetles kill the tree. The red color is a late sign, so the attack usually happened the season before.
Are pitch tubes always mountain pine beetle?
No. Other bark beetles and even injuries can cause pitch. A pitch tube is a reason to get an expert look, not a final answer.
Should I remove a dead pine right away?
If it is close to a house, road or power line, yes, because dead trees can fall without warning. Away from structures, the timing is less urgent. Ask a pro to look at it.
Can I move firewood from a beetle-killed tree?
Check local rules first, because some areas limit moving infested wood. In general, wood left with bark on can still hold beetles. Ask your state forestry office.
Does the beetle hurt people or pets?
No. The risk is the dead tree falling and the extra fire danger in dry, dead stands. Treat dead pines near your home as a safety job.
Can Lirevon diagnose mountain pine beetle on my tree?
No. Lirevon is a remote marketing team for tree service companies and does not do tree work. This page is general information, not a diagnosis. A certified arborist or your county extension office can confirm what is wrong with your tree.
How do I find a good local pro for this?
Search Google Maps for certified arborists or tree services near you, read their reviews and ask for proof of insurance. Get two or three written quotes. Our guide on how to hire a tree service lists the questions to ask.
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