Mountain Pine Beetle - Banff Park
Mountain Pine Beetle information from Banff National Park
Mountain Pine Beetle - Banff
The mountain pine beetle (MPB) is a naturally occurring
insect of the Rocky Mountain ecosystem. These small
cylindrical insects attack and kill mature trees by boring
through the bark and mining the phloem – the layer
between the bark and wood of the tree. When conditions
are favourable, populations of MPB can increase and large
numbers of trees can be infected, killing large areas of
mature lodgepole pine. This natural process is important to
the forest ecosystem because, as a natural disturbance, it
sets the stage for forest regeneration.
Life Cycle of Mountain Pine Beetle
MPB normally have a one-year life cycle. In
late summer, the adults, who are about 5 mm
(1/4”) long, leave the infected trees in which
they have developed. They then seek out and
colonize living, green trees, as well as
search for mates.
The beetles tunnel into the tree and lay eggs
in vertical galleries under the
bark. After the eggs hatch, the
grub-like larvae spend the winter
feeding under the bark. Larvae
pupate in the spring and emerge
as adults from July to September.
A key part of this cycle is the
transmission of blue-stain fungi
from the beetle to the tree. The
spores of these fungi are brought
into the tree by adults during
colonization.
Fungi grow within the tree and,
together with bark beetle feeding,
weaken it. This mutual network
of beetle galleries and blue stain fungi
disrupts the movement of water within the
tree and rapidly kills it. The fungi give a
blue-grey appearance to the sapwood.
What to Look For:
-red needles on the crowns of trees.
-eggs or larvae under the bark, or their
galleries under the bark.
-“pitch tubes” – bubbles of resin on the
trunk where beetles tunnel into the bark.
-“sawdust” at the base of a tree or in
bark crevices.
-woodpecker activity, such as holes in
the trunk and bark chips on the ground.
What Is the History of MPB
in the Mountain Parks?
The MPB is present in all mountain
national parks, but has only reached
epidemic levels in Kootenay, Yoho
and Waterton. In the 1940s, there
was a major MPB outbreak in
Kootenay National Park. 65,000 ha
of pine forest were affected. A
minor outbreak in Banff National
Park affected 4000 ha. In the 1970s,
a major MPB epidemic moved
from the US Rocky Mountains into
southeastern BC and southwestern
Alberta, including Waterton Lakes National
Park. Through the 1980s, the beetles moved
through Kootenay National Park. A small
outbreak occurred in southern Banff
National Park in the early 1980s.
In 1997, the annual insect and disease
survey found that the beetles had dispersed
across the Continental Divide into the
Brewster Creek, Healy Creek and Bryant
Creek drainages of Banff National Park.
Since then, the beetle population has grown
and migrated eastward into the warmer,
drier forests of the Bow Valley, including
areas outside Banff National Park.
What We Are Doing About MPB:
Parks Canada’s policy provides the
following direction to Banff National Park:
1. Native insects and diseases are natural
ecological processes that should be allowed
to proceed without interference if possible.
2. Where insects or disease pose a serious
threat to provincial lands, intervention may
occur, provided that it is effective and does
not damage the park ecosystem.
To achieve both of these objectives, Banff
National Park has established two different
areas where different strategies are applied:
Long term management zone:
Prescribed fire are lit to reduce the
extend extent of of MPB habitat, thus
preventing a large build-up of the beetle
population.
Short term management zone:
Beetle colonized are burned by
prescribed fire, cut and removed, or cut and
burned to slow the growth growth of the
beetle population. Pheremone baiting is used
to concentrate beetle colonization to known
areas.
Summary
MPB is a dynamic ecological process that
has both large-scale ecological benefits
within the park and the potential for largescale
economic impacts on industrial forests.
As such, it requires an adaptive management
approach that integrates the objectives of
many land managers.
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