Cultural:
Thin pine stands to reduce the hazard of MPB attack. Guidelines on
thinning pine stands are available from Serve Foresters, OSU Forestry
Extension, and OSU Extension Circular 1106 (September, 1982). Thinning
may reduce tree mortality even if performed in the midst of a MPB outbreak.
Thinning operations should be conducted so that slash accumulations do not
provide breeding sites for another pest, the Oregon pine engraver beetle.
Cut, pile and burn infested trees in the late winter or early spring before
beetles emerge. CHECK WITH LOCAL STATE FORESTRY OFFICE ON BURNING
REGULATIONS!
Chemical:
Spray a carbonyl formulation (Sevin) onto the trunk of individual high value
pine trees near homesites. Pines are protected only if the spray is
applied before beetle flight in July. See OSU Extension Circular 1085
of instructions.
REMEMBER WHEN USING PESTICIDES, ALWAYS READ AND FOLLOW THE LABEL!
Do not cut firewood when pine crowns are yellow (May-June). Wood cut
at this time may carry adult beetles to homesites where they will soon
emerge and seek new hosts. Any wood cut from declining pine (those
with yellow-green foliage) should be stored away from any living pines and
covered with clear plastic to emerging beetles. See OSU Extension
Publication FS 279 (September, 1981) for procedures.
Figure 1: Cycle of Mountain Pine Beetle attack and tree decline
Figure 2: A- Mountain Pine Beetle gallery pattern located under the
bark of an infested tree (gallery length 12"-36", wood grain runs
vertically.
Figure 2: B- Cross section of beetle killed pine showing the location of
stained wood.
Figure 3: Mountain Pine Beetle and Larva
Figure 4: Pitch Tubes on Bark of Ponderosa
For more information see
USFS Newsletter on
MPB.
Handling Infested Firewood:
Control:
Figure 3
Figure 2
Figure 1
The cycle of beetle attack and tree decline is shown in Figure 1.
Trees attacked during the current year will have pitch tubes on the trunk,
but crowns remain green. Pitch tubes do not always mean a tree will
day, particularly if the MPB attacks are on Ponderosa Pine. Tree death
is confirmed when the crown changes color in May-July of the year following
the attack. Removing the bark of infested trees will reveal a gallery
pattern characteristic for this beetle (Figure 2). The sapwood from
the MPB infested tree is darkly stained by a fungus the beetle introduces in
the tree.
Host
PO Box 1987
Sunriver, OR 97707
541.593.8360
The following information was written and published by the Oregon Department
of Forestry
Certified Arborist
Importance
Infestation Characteristics:
Look For:
Lodgepole Pine, Ponderosa Pine, Western White Pine and Sugar Pine.
The Mountain Pine Beetle (MPB) is one of the most destructive tree-killing
beetles in Oregon. Annual pine mortality from this beetle averaged
more than one million acres between 1976 and 1985. The threat of
beetle infestation in older, unmanaged pine stands is great enough to
influence forest management decisions in much of Eastern Oregon.
Clumps or large areas of pines with red crowns and tubes of pitch exuding
from the trunk. Over stocked pine strands over 60 years old with a
breast height diameter (dbh) between 6"-26" for Lodgepole and 6"-40" for
Ponderosa Pine are susceptible to MPB attacks.
Seasonal changes in the appearance of a tree's crown can indicate beetle
attack. During May-June, the foliage of pines attacked the pervious
year turns yellow. By July, the crowns of these trees are red.
In July-August, pitch tubes are present on the park of newly attacked trees,
but the crowns remain green.
Pine Beetle
Figure 4
