Mountain pine beetle
The mountain pine beetle (MPB), Dendroctonus ponderosae, is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton and measures about 5 millimetres, about the size of a grain of rice.
Mountain pine beetles inhabit pines, particularly the Ponderosa Pine, Lodgepole Pine, Whitebark Pine, Scots Pine and Limber Pine. The bristlecone pines and pinyon pines are less commonly attacked. During early stages of an outbreak, attacks are limited largely to trees under stress from injury, poor site conditions, fire damage, overcrowding, root disease or old age. As beetle populations increase, the beetles attack the largest trees in the outbreak area.
The beetles kill the trees by boring through the bark into the phloem layer on which they feed and in which eggs are laid. Pioneer female beetles initiate attacks, and produce pheromones which attract other beetles and results in mass attack. The trees respond to attack by increasing their resin output in order to discourage or kill the beetles. It isn't the number of pitch-out tubes that kill the pine tree but the beetles carry blue stain fungi which, if established, will block the tree resin response. Over time (usually within 2 weeks of attack), the trees are overwhelmed as the phloem layer is damaged enough to cut off the flow of water and nutrients. In the end, the trees starve to death, and the damage can be easily seen from the air in the form of reddened needles. Entire groves of trees after an outbreak will appear reddish for this reason. Usually, the older trees die first. After particularly long and hot summers, the mountain pine beetle population can increase dramatically, which leads to the deforestation of large areas. Current outbreaks are in Rocky Mountain National Park.
Integrated Pest Management (IPM)
There are some natural IPM defenses against the MPB. Owners nail to a tree an “anti-aggregation pheromone” in a small packet, which mimics the chemical scent given off by beetles when a tree is full of insects. It can work when beetles are not too numerous, but at some point the beetles are not deterred.
The US Forest Service tested chitosan, a eco-friendly biopesticide, to pre-arm pine trees to defend themselves against MPB. The US Forest Service results show AgriHouse's EPA registered ODC Collodial Chitosan elicited a 40% increase in pine resin (P<0.05) in Southern Pine Trees. The US Forest Service applied 1 ml ODC chitosan in 10 gallons water to the ground area within the drip ring of the loblolly pine tree. The ODC chitosan application was repeated three times from May through September in 2008. The ODC chitosan was responsible for eliciting natural defense responses of increased resin pitch-outs with the ability to destroy 37% of the pine beetle eggs. Dr. Jim Linden, Microbiologist, Colorado State University, states that the chitosan increased resin pitch-outs push the boring pine beetle out of the tree, preventing the MPB from entering the pine tree and spreading blue stain mold.
Approximately two weeks following oviposition, pine beetles hatch as white larvae. They dig into tree bark where they spend the winter, then grow up to 7 mm long in the spring. The pupal stage ends in the late spring or early summer, and from mid-July to mid-August, the beetles leave their tunnels and fly to new trees. Female beetles release pheromones to attract males and encourage mass attacks. The lifespan of a single pine beetle is about one year.
Temperatures down to −30 °C to −40 °C (−22 °F to −40 °F) for at least several days, or at least twelve hours of −40 or lower, kills most mountain pine beetles.
The current outbreak of mountain pine beetles is ten times larger than previous outbreaks. In Wyoming and Colorado in 2006 there were 1 million acres (4,000 km2) of dead trees. In 2007 it was 1,500,000 acres (6,100 km2). In 2008 it is expected to total over 2 million acres (8,100 km2). It may be the largest forest insect blight ever seen in North America. Climate change has contributed to the size and severity of the outbreak , and the outbreak itself may, with similar infestations, have significant effects on the capability of northern forests to remove greenhouse gas from the atmosphere. Huge parts of central British Columbia along with parts of the forests of Alberta have been hit badly. The recently mild winters have British Columbia's forestry officials worried because the beetles will have a devastating impact on an ecosystem which may be ill-equipped naturally to deal with it. Fortunately, if properly contained, the pine beetle can be burnt out, but such containment is prevented during cases in which the infection has towns, homes, and cities completely surrounded. A cold snap in early 2008 was hoped to have dropped the pine beetle population to more manageable levels. However, preliminary results from the summer of 2008 indicate that the cold winter was less successful at killing pine beetle than predicted.
As of 2008, there was also a large outbreak in Colorado. The largest problem in the eradication of the beetle is that homes in the area are close to the infected trees, so that a controlled burn could be problematic. Furthermore, since the trees that are being hit are older and the Ponderosa Pines affected are stimulated to spread seeds by heat of around 130 degrees from either fire or solar radiation much forest will die before it is renewed.
A lodgepole pine tree with a "pitch out".
A lodgepole pine tree infested by the mountain pine beetle, with visible "pitch outs".
A pine tree forest north of Breckenridge, CO showing infestation in 2008
Effect on carbon cycle
Researchers from the Canadian Forest Service have studied the relationship between the carbon cycle and forest fires, logging and tree deaths. They concluded that by 2020 the pine beetle outbreak will have released 270 megatonnes of carbon dioxide into the atmosphere from Canadian forests. There is yet to be an accepted study of the carbon cycle effect over a future period of time for North American forests.
- Community Economic Diversification Initiative (CEDI) an important component of Federal Mountain Pine Beetle (MPB) Program provided by Western Economic Diversification Canada
- US Forest Service
|Wikispecies has information related to: Mountain pine beetle|
- ^ Leatherman, Forest Entomologist, CSU, D. (2009-06-01). "THE MOUNTAIN PINE BEETLE: KEYSTONE SPECIES OR DARTH VADAR? - 2009 ESTES PARK TREE SYMPOSIUM". Colorado State Forest Service. http://www.estesnet.com/publicworks/Tree%20Board/DaveLeathermankeystoneordarthvadar.pdf.
- ^ Robbins, Jim (2008-11-17). "Bark Beetles Kill Millions of Acres of Trees in West". New York Times. http://www.nytimes.com/2008/11/18/science/18trees.html?_r=1&scp=1&sq=robbins%20beetles&st=cse.
- ^ Mason, M. (1997), Defense Response in Slash Pine: Chitosan Treatment Alters the Abundance of Specific mRNAs, US Forest Service, http://www.treesearch.fs.fed.us/pubs/5322
- ^ Klepzig, K. (2003), Cellular response of loblolly pine to wound inoculation with bark beetle-associated fungi and chitosan, US Forest Service, http://www.treesearch.fs.fed.us/pubs/5322
- ^ O'Toole, Erin (2009-09-10). "Solution for Pine Bark Beetles May Help Front Range Trees". NPR Morning Edition - KUNC 91.5 FM Greeley, CO. http://www.publicbroadcasting.net/kunc/news.newsmain/article/1/0/1552856/Regional/Solution.for.Pine.Bark.Beetles.May.Help.Front.Range.Trees.
- ^ Porter, Steve (2009-09-11). "Arming trees against pine beetle invasions". Northern Colorado Business Report. http://ncbr.com/article.asp?id=102064.
- ^ Mountain Pine Beetle, Alberta Sustainable Resource Development
- ^ Mountain Pine Beetle - Ministry of Forests and Range - Province of British Columbia
- ^ a b "Beetles may doom Canada's carbon reduction target: study". 2008-04-23. http://www.terradaily.com/reports/Beetles_may_doom_Canadas_carbon_reduction_target_study_999.html. Retrieved 2008-04-28.
- ^ "Bark Beetles Kill Millions of Acres of Trees in West". 2008-11-17. http://www.nytimes.com/2008/11/18/science/18trees.html. Retrieved 2009-02-09.
- ^ "In the Rockies, Pines Die and Bears Feel It". 2007-01-30. http://www.nytimes.com/2007/01/30/science/30bear.html?ref=science. Retrieved 2009-02-09.
- ^ "Mountain pine beetle and forest carbon feedback to climate change". 2008-04-24. http://www.nature.com/nature/journal/v452/n7190/abs/nature06777.html. Retrieved 2009-07-16.
- ^ Platt, Michael (2008-03-13). "Millions of tiny, pine beetle corpses!". Calgary Sun. http://calsun.canoe.ca/News/Columnists/Platt_Michael/2008/03/13/4988766-sun.php.
|Wikimedia Commons has media related to: Dendroctonus ponderosae|
- The Falldown Documentary- A look at the devastating impact of the beetle on British Columbia and Canada's Economy
- BC Pine Beetle Information Portal
- Canada's Forests Beetle Attack - The Economist
- Rocky Nat'l Park Fights Pine Beetles With Burner - CBS4Denver
- Deaths of trees 'catastrophic' - Rocky Mountain News
- Pherotech International, Mountain Pine Beetle and other Bark Beetle controls through use of Integrated Pest Management Plans
- Washington Post article: 'Rapid Warming' Spreads Havoc in Canada's Forests
- Natural Resources Canada site on the Mountain Pine Beetle
- Rocky Mountain pine beetle epidemic devastating to Colorado forests
- Detailed information from Alberta Forest Health about the mountain pine beetle's life cycle and what to look for in beetle infestations
- British Columbia Ministry of Forests and Range Library - Bibliography of Mountain Pine Beetle Publications
- British Columbia Forestry Ministry - Mountain Pine Beetle Action Plan, information and FAQ
- David Suzuki Foundation - Call for ecosystem-based management
- British Columbia Ministry of the Environment Mountain Pine Beetle FAQ
- BC MPB outbreak projection update w/ 2005 data
- Provincial aerial survey of MPB 2006
- Map of projected percentage of pine killed in British Columbia by 2012
- Genomics project on the three interacting organisms (beetle, fungus, and tree)
- Grande Alberta Economic Region's Mountain Pine Beetle pages
- Towards Transformation: The Economic, Social and Environmental Costs of the Mountain Pine Beetle in the Grande Alberta Economic Region
- Flickr MPB image pool
- The TRIA Project: Mountain Pine Beetle System Genomics
- DISPOSAL OF TREES AFFECTED BY THE PINE BEETLE: THE DILEMMA AND WHY AIR CURTAIN BURNERS SHOULD BE USED
- Non-profit organization, working in conjunction with universities, to develop new technologies using pine beetle kill for reclamation and energy needs