Pine bark beetle management

Forest management

logging equpiment doing a thinning

Damage from pine bark beetles can potentially be avoided with well-timed thinning and quick removal of wind- or fire-damaged conifers.

During drought there is heightened risk for bark beetle population buildup and damage. We observed this in 1976, 1987, 1988, and 2021.  To reduce the risk of a pine bark beetle infestation:

  • If you are planning thinning operations, follow slash removal guidelines regardless of drought conditions (see table below).
  • Consider postponing pine thinning until drought conditions are over, if possible.
  • Monitor pines from May through August and be prepared to salvage if you see widespread signs of infestation

When pines are damaged by strong winds or fire, thinning pine stands, or clear-cutting pine adjacent to younger pine stands, follow these guidelines in Minnesota* to avoid problems with bark beetles in the remaining conifers, and to avoid bluestain This link leads to an external site. fungi in pine lumber:

Time of damage or cutting


When to take action

December 1-May 31

Haul and destroy logs and slash more than 3" in diameter

Before June 1

June 1-August 31

Haul and destroy logs and slash more than 3" in diameter

Within 3 weeks of damage or thinning

September 1-November 30

May leave slash on site


*Note: For areas in far southern Minnesota, logs and slash may have to be removed before May 15 if cut from early December to mid-May, particularly if the early spring has been warmer than average. For areas in far northern Minnesota, logs and slash might not have to be removed until mid-June if the early spring has been colder than average.

Residential trees

Fresh firewood by pine tree infested with pine engaver beetles.Preventing attack by pine bark beetles is best. Keep trees well-watered during periods of dry weather. Promptly haul large (greater than 3" in diameter) pine debris away to an approved facility or chip up broken branches or snapped-off pines after a storm. Make sure fresh firewood is never stored close to healthy trees, since freshly cut pine firewood can provide pine bark beetle habitat.

Other Sources

Managing pine bark beetle damage in Minnesota’s forests

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