Mountain Pine Beetle

What is a Mountain Pine Beetle (MPB)?

The Mountain Pine Beetle (Dendroctonus ponderosae) is a naturally occurring bark beetle native to western North America. It is about the size of a grain of rice. 

 

The MPB Lifecycle

Female beetles bore into the bark of pine trees in mid-summer, awaiting the arrival of males to mate and deposit eggs.  In August, the larvae hatch and begin mining horizontal galleries, destroying the conductive tissue of the tree and disrupting the water and nutrient flow of the host tree. Within one month of the attack, a pine tree can be killed by the larvae. The larvae overwinter in the tree, protected from the cold by the bark. In late June to early July, the larvae develop into adult beetles. Adult beetles exit the trees in mid-July to begin their flight to new pine trees.

 

Why are MPB a problem?

Under normal population levels, the beetles help to keep the forest’s ecosystem in check by attacking weak and old pine trees. This allows younger pine to regenerate. Historically, cold winters have helped to manage the MPB population. However, since 1996, beetle populations have flourished and continue to move eastward across Canada.  Large populations mean more host trees are needed.  As beetle populations move eastward looking for new hosts, they are assisted by strong winds, which can carry them into new territory.  Large inflights due to strong winds in 2006 and 2009 did just that - carrying beetles approximately 400 km from central B.C. to the Grande Prairie and Peace River regions, as well as Whitecourt and Slave Lake areas, destroying pine forests along the way.

 

What is Brazeau County doing?

In 2021, Brazeau County was awarded a Provincial grant to assist in the MPB fight. Contractors will be surveying municipal land throughout the County to identify areas hit by the beetle.  Control and treatment of infected pine trees will be conducted by the contractors to help stop the spread. It is crucial this work be completed prior to June 30 to destroy the beetles before they bore exit holes in infected trees and begin their flights to attack new trees.

 

How to identify MPB activity

The most recognizable sign that MPBs have attacked is the presence of red trees.  However, red trees alone do not necessarily equate to a beetle attack. Needle discoloration is also a common sign of environmental damage caused by drought, flood, injury, or soil deficiency to name a few. When looking for beetle activity, the first question to ask is “Is it a pine tree?” Signs of MPB include pitch tubes oozing cream-coloured resin as the tree fights to “pitch” the beetle out, and boring dust around the base of the tree from the beetles boring under the bark.  Under the bark, you will see J-shaped galleries where eggs are deposited.

  

Pine tree                                   Pitch tubes          Galleries

 

Control of Infested Trees

Private land owners who have confirmed attacks should treat infested trees before the end of June, prior to new flight.  This ensures all life stages of the beetle are destroyed.  Treatment options include: peel standing, whole tree peeling, and fall and burn.

 

Does cold weather help mortality rates?

It depends on how well the beetles were prepared for the temperature fluctuation. A fact sheet is available here.

 

Tracking movement of MPB infestations

Provincial MPB maps are available here

For further information, please visit the Government of Alberta website here.

Mountain pine beetle information cards can be viewed here.