Pine bark beetles in eastern Washington and central Oregon

Three beetles, three different trees

East of the Cascades, three native beetles do most of the pine killing. They are not invasive and there is no quarantine for any of them; the damage tracks drought, crowding and fresh slash.

The City of Spokane names western pine beetle and the pine engraver as the two that matter most in its yards. A fourth, the red turpentine beetle, leaves large pitch masses on the lower trunk but is rarely lethal, according to DNR.

How bad it is right now

Washington’s 2024 Forest Health Highlights (DNR and USDA Forest Service) mapped western pine beetle mortality in ponderosa pine on about 32,800 acres in both 2023 and 2024, above the 10-year average of 25,700 acres, after a peak of 44,300 acres in 2022. The report calls recent drought “likely an important driver” and notes marked increases in Klickitat County and eastern Yakima County.

Mountain pine beetle covered about 83,600 acres in Washington in 2024, down from 90,200 in 2023, mostly in lodgepole pine; ponderosa accounted for 7,300 acres. Pine engraver acreage doubled from 900 to about 1,850 acres. Mapped areas include the Simcoe Mountains, Manastash Ridge in Kittitas County, the Lake Chelan-Sawtooth area and Mount Bonaparte in Okanogan County.

In Oregon, ODF’s 2024 report counts western pine beetle on 23,000 acres of drought-stressed ponderosa pine east of the Cascades and mountain pine beetle on 16,000 acres of dense lodgepole or drought-stressed ponderosa. ODF’s mountain pine beetle fact sheet puts the 2007–2016 average at 380,000 acres a year, which shows how far an outbreak can swing.

Signs on a yard pine

• The whole crown changes color. Spokane’s guidance: needles fade to yellow, then orange. ODF says western pine beetle foliage goes pale green, then yellow, then brownish-orange. With mountain pine beetle the fade often shows between May and July of the year after the attack, so the beetles have usually left by the time you notice.
• Only the top third is dying. Topkill in the upper third of the crown is often the first obvious sign of pine engravers (ODF).
• Pitch tubes. Mountain pine beetle tubes are 13–25 mm across and obvious; western pine beetle tubes are usually under 6.5 mm and easy to miss; Ips seldom makes them (ODF, DNR).
• Orange-tan or reddish-brown boring dust in bark crevices and at the base. In drought, trees may show dust without pitch tubes (ODF).
• Woodpeckers flaking off bark to get at larvae (ODF, Spokane).

Not every brown pine is a beetle kill. Drought scorch, winter injury and needle diseases can look similar from the ground, and ODF publishes a separate drought-stress fact sheet for that reason. Confirm before you cut a tree that might recover; the checklist on how to tell if a tree is dead covers the scratch test and bark checks.

Remove, and when

Spokane’s advice is blunt: once a tree is infested, removal is usually the right answer, because pesticides do nothing for a tree that is already infested. Timing matters because the wood is still full of the next generation.

A dead pine near a house is a safety question first. When the tree is in reach of a house, a fence or a driveway, have a certified arborist rate it; what that looks like is on tree risk assessment, and the removal side is on dead tree removal.

Modeled estimate, not quotes (method): a 50–80 ft pine models at $1,700–$3,400 in Washington and $1,800–$3,600 in Oregon, with chipping and haul-away but no stump; add 25 percent if the trunk is within 10 ft of a structure. See tree removal cost.

Slash and firewood: the step most people get wrong

Fresh pine slash is pine engraver breeding material, and with flights from April and a new generation every 4–6 weeks (ODF), rounds stacked beside healthy pines in spring can feed an attack on those trees the same summer. The agencies agree on the fix:

1. Watch the 3–8 inch pieces. ODF names pine slash 3–8 inches in diameter as the main target; DNR says to avoid creating green pine slash over 3 inches from early winter through mid-summer.
2. Cut in fall if you can. Slash created October–December can be lopped and scattered in the sun and will dry before the April flight (ODF).
3. If you cut January–September, burn, chip, masticate or bury the slash before April, or within two months (ODF). Chipping to under 3 inches works.
4. Do not stack green firewood near live pines (Spokane). Split it and stack it in the sun away from the trees; for slash, ODF also describes solarizing under clear plastic, which only works if the wood reaches 113°F.

Burning is often off the table in town. Spokane Regional Clean Air Agency prohibits residential yard-debris burning for most residents, including inside the urban growth areas. Check Washington yard debris burning rules or Oregon yard debris burning rules before you light a pile; chipping is the safer default.

Permits for a beetle-killed pine

• Bend: removal on a site of one acre or smaller with an existing dwelling is exempt from the tree code (BC 16.40.020); larger sites and development follow the Tree Performance Standards.
• Spokane: the Urban Forestry permit page says no permit is needed for trees on private property; street and planting-strip trees need a city permit (SMC 12.02.960).
• Klamath Falls: no private-tree permit, but the code bars keeping dead or hazardous trees (KFC 5.632, 3.735), so a dead pine is your obligation.

Other cities are covered in Oregon tree removal permits and Washington tree removal permits. Dead trees are the easy case almost everywhere.

Keeping the rest of your pines alive

Every agency says the same thing in different words: beetles take the stressed tree first. Spokane asks homeowners to water pines during drought and to irrigate deeply but intermittently so roots grow down. ODF and DNR both call thinning essential for prevention in forested lots; ODF’s western pine beetle sheet gives a target of 55–70 percent of the basal area needed for full site use. DNR adds a caution: thin clumps only where no root disease is present.

On a wooded lot in Deschutes County or near Goldendale or Cle Elum, thinning also serves fire safety. The legacy guide on creating a defensible space covers spacing around the house. The tree itself is described on ponderosa pine, and other pests are listed on pests and diseases.