BARK BEETLE INFORMATION
Bark beetles are a serious threat to susceptible landscape trees. Presently, pine bark beetle has declined to regular levels but the turpentine beetle levels have been on the rise.
The prevalent beetle attacking pine trees in our area are Mountain Pine Beetles (MPB) and Western Pine Beetles (WPB). To a lesser extent Douglas Fir trees are being attacked by Douglas Fir Beetles. The MPB can attack and kill most pine trees over 10cm in diameter including lodgepole pine, ponderosa pine, western white pine, white bark pine and limber pine. Larger diameter and stressed trees are more susceptible. The WPB normally only attack ponderosa pine and can attack and kill any ponderosa pine greater than 10cm in diameter but the stressed trees are usually more susceptible initially. Historically, WPB have infested ponderosa pine trees in the Okanagan Valley but now MPB are coming down into the valley from higher elevation lodgepole pine infested trees and attacking ponderosa pine trees as well.
For information on biology and life-cycle, etc. the Forest Service web site will help . . (www.for.gov.bc.ca/hfp/mountain_pine_beetle/)
Increasing pine bark beetle populations are posing a greater threat to our pine trees. Some procedures than can prevent or reduce the potential damage impacts are:
- Sanitize the area by examining susceptible trees for beetle attack and removing known currently infested trees prior to beetle flights.
- Keep trees healthy and reduce tree stress. Weak or stressed trees can attract bark beetles. Trees can be stressed due to reduced root area, trunk injury, soil or other material placed over root zones and lack of adequate moisture and nutrients. Stress conditions should be reduced and possible extremely weaked trees removed.
- Prevent tree injury especially during beetle flight period (May-Sept). Injury stresses the trees and makes them more susceptible to beetle attack.
- Check trees every second week during beetle flight periods. This is especially important if there are known currently infested trees within 300 m of your trees. Examine the trees for evidence of attack such as boring dust and pitch tubes.
- Verbenone beetle repellent pouches can be placed on susceptible trees. They provide some tree protection when beetle populations are low.
- Application of pesticide sprays on tree boles can provide some limited protection. Pesticide use registration is not for all beetles.
- A new procedure of wrapping the tree trunks with fine screening can be used but has some application limitations.
These management strategies can minimize the risk of trees being attacked but do not provide guaranteed control.
Monitoring during and after beetle flight periods is very important. Early attack detection will enable landowners to select the appropriate beetle control and tree management strategy.
Thanks to Eric Haupt, Forest Health Consultant
** Call us to schedule a monitoring service or for more information @ 250 542-8719