Mountain Pine Beetle - Frequently Asked Questions

Last Review/Updated: January 22, 2008

What is the mountain pine beetle?

The mountain pine beetle (Dendroctonus ponderosae Hopkins) is a member of the bark beetle family, and is the most damaging insect pest of pine trees in western North America. The adult beetles are black and small, just 5-7 mm long, while the larvae look like small maggots under the bark.

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What damage can they cause?

Mountain pine beetles mass attack and kill mature pine trees within a year. In mid-summer, the adults bore into suitable host trees and lay eggs in the bark. The larvae hatch and feed within the bark of the tree. Larvae develop into pupae, then to adult, and fly to the next host. The lifecycle normally takes one year to complete. The following spring, the needles of the attacked tree fade to yellow and then to reddish-brown. For more details, click here.

The adult beetles introduce blue-stain fungi into the tree when they attack. These fungi, along with insect feeding, kill the tree by cutting off paths for nutrients and water. Each female lays 60-80 eggs, enabling populations to grow very quickly. There are often enough insects emerging from one tree to attack 15 additional trees.

If the beetles are not managed while the populations are low, severe damage to pine stands can result. Outbreaks can destroy thousands of hectares of mature pine forest in a single year. In 2004, over 7 million hectares were infested in B.C. In cooperation with the forest industry, Alberta Sustainable Resource Development monitors beetle populations in various areas within the forested Crown land and attempts to control infestations before they reach epidemic (outbreak) levels.

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Are mountain pine beetles common to Alberta?

Most of Alberta is outside of the beetles normal range of distributions, due primarily to climate. Alberta's winter is sometimes too severe for the beetles to survive.

There have been historical outbreaks in southern Alberta when population levels were high in B.C. and Montana in areas near the Alberta borders. The most recent outbreak occurred in the late 1970s to the mid-1980s. Beetle populations have been on the rise in Alberta since 2000.

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Where do they live?

The range of mountain pine beetle extends from Mexico to British Columbia. They breed in lodgepole, ponderosa, whitebark, limber, and white pines. The beetles prefer mature (over 80 years old), large trees. Beetles may attack younger trees, but they are usually less successful. For more details, click here.

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How far can they fly?

Most species of bark beetles are strong flyers. Though not common, mountain pine beetles can potentially disperse over great distances if the winds are in their favour. In 2006, the province experienced a large influx of beetle from British Columbia due to wind. They were widely dispersed across north-western regions were they are not commonly found.

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What is their role in the environment?

In their normal habitats, beetles are stand-replacing factors. Beetle outbreaks remove the over-mature pine from the stand and allow other tree species to take over. However, this beetle may not play this role in Alberta's pine forests that have evolved to the present day without the pine beetle in their ecosystem. The mountain pine beetle will be very destructive in these environments. It may have detrimental impacts on the native fauna and flora, as well as the watersheds, soils, water quality and natural ecosystem succession.

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Why are the mountain pine beetle infestations becoming more extensive?

Modern fire suppression has resulted in large areas of pine forests with over-mature trees, which are more susceptible to beetle attack. In the past, most of Alberta has been outside the mountain pine beetle's normal range of distribution due to the harsh winter conditions. However, with the recent milder winters, these beetles have been more successful in parts of Alberta.

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Do they have any natural enemies?

Yes, birds, especially woodpeckers, eat a large number of insects. In addition, while the birds feed, they remove bark and expose the remaining insects to the elements.

Insect parasites, predators and fungal diseases also attack bark beetle larvae. During outbreaks, these organisms probably have little effect on the pine beetle population.

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How are they naturally controlled?

Healthy trees defend against beetle invasion by producing resin. Resin, or pitch, flushes the adult beetles out of the tree. This is effective when only a few beetles attack a tree, but if many insects attack, or if the tree is stressed, resin flow is reduced.

Temperature is also an important factor in determining beetle survival. Mountain pine beetle larvae must develop to a certain stage to tolerate cold winter weather (-40¡C inside the bark). Late spring frosts and cool summers may delay beetle flight and subsequently slow brood development and increase overwintering mortality. The last two outbreaks in Alberta were ended by unseasonably cold temperatures (-30¡C) in October and November.

Depletion of pine hosts also controls beetle populations. Once the beetles kill all the old, large pines in an area, they must fly to find more hosts. While flying, the beetles are susceptible to dehydration, predation and the possibility of not finding a suitable tree.

Wildfire also removes the over-mature pine stands. A fire will damage and destroy many pine trees. However, unless the fire burns really hot, some beetles may still survive in trees that are partially burned. These beetles may then easily attack nearby weakened trees.

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How will an infestation be controlled?

Alberta Sustainable Resource Development is working co-operatively with Community Development, Parks Canada, BC Ministry of Forests, Municipalities, forest industry, and other concerned stakeholders to ensure all values at risk are considered when managing the beetles.

Since the beetles spend most of their life in the bark, control will focus on treating individual trees. Trees killed by the beetle in the previous summer are identified by aerial surveys. The locations are then confirmed by ground checks. For more details, click here.

The only effective way of managing beetles is to remove the infested trees before the beetles emerge and fly. Removal of trees can involve cut and burning, cut and peeling the bark or milling the wood.

If an infested tree cannot be treated before the flight, chemical attractants called pheromones are used. The pheromones lure most of the newly emerged beetles to a small area until the affected trees are treated.

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Who will manage infestations?

Land in Alberta is managed by a number of different stakeholders such as private, provincial, federal and municipalities,. Although ASRD is the lead agency when managing MPB, consultation with all stakeholders and coordination of efforts among all land mangers is critical. The department works closely with the forest industry, municipalities, other provincial ministries and the federal government to undertake treatments in Alberta. Further detail can be found in the Mountain Pine Beetle Infestation Management Responsibilities and the Alberta’s Mountain Pine Beetle Action Plan.

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Why prevent an outbreak?

Albertans are committed to proactive management of Alberta's forest resources. Productive, healthy, diverse and aesthetically pleasing forest ecosystems are essential to achieve environmental, social, cultural and economic goals that contribute to sustainable development and a high quality of life.

Active, sustainable management of Alberta's forest resources remains an integral piece of Alberta Sustainable Resource Development's mandate. Controlling mountain pine beetle infestations continues to be a focus in maintaining the health of our forests. Successful management of beetle infestations will help reduce the accumulation of wildfire fuel and protect the wildlife habitats of Alberta's eastern slopes.

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What can you do to help?

Albertans can play an important role in preventing the spread of forest pests. Here are some ways you can help save Alberta's forests from mountain pine beetle:

  • Avoid transporting firewood from one area to another, especially if the bark is still attached. Mountain pine beetle and Dutch elm disease can be transported in firewood to Alberta
  • Learn to recognize symptoms of mountain pine beetle attacks. For more details, click here. Here are the most common symptoms to look for:
    Red Trees
    The mountain pine beetle prefers to attack large pine trees greater than 10 metres tall or with a diameter greater than 24 centimetres. Trees successfully attacked by the mountain pine beetle during the previous season begin to turn yellow in June and July, and reddish brown by August.
    Pitch Tubes
    The tree will often produce a large amount of sap to help flush out invading beetles. The sap often forms irregular creamy coloured globs called pitch tubes on the outside of the tree bark; it looks similar to crystallized honey.
  • Report suspicious pest findings especially red pine trees, or get additional information by calling 310-BUGS (2847)
  • Learn all you can about mountain pine beetle issues, especially in areas of known mountain pine beetle infestations, and periodically visit this web site for updated information.

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Are there contract opportunities for vendors?

Vendors requiring information about contract opportunities with our mountain pine beetle survey and control operations, including contract requirements, please visit the Alberta Purchasing Connection website.

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