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 millimeters, about the size of a grain of rice.
Mountain pine beetles inhabit ponderosa, lodgepole, Scotch and limber pine trees. 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.
Pine beetles kill 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, producing pheromones that attract more beetles. The trees respond to attack by increasing their resin output to discourage or kill the beetles. Pine beetles carry blue stain fungi which, if established, will block the tree resin response. Within about two weeks of a beetle attack, the trees starve to death as the phloem layer is damaged enough to cut off the flow of water and nutrients. Older trees usually succumb first. After particularly hot summers, the mountain pine beetle population can increase dramatically, deforesting large areas. After an outbreak, entire groves of trees will appear red when viewed from above. Rocky Mountain National Park and large portions of Colorado have suffered recent pine beetle outbreaks.
Integrated Pest Management (IPM)
There are some natural IPM defenses against the MPB. An “anti-aggregation pheromone” may be attached to a tree in a small packet, mimicking 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. One ml ODC chitosan per 10 gallons water was applied 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.
The most effective way to manage pine beetles is to use the integrated pest management (IPM) strategy. This includes removing and cutting dead trees as well as thinning trees to maintain a healthy forest. Spraying is helpful in smaller scale situations where a few high value trees are to be saved. Verbenone, an anti-aggregate pheromone, can be used in smaller-scale operations when spraying is not an option.
Spraying is one of the more effective ways of protecting a pine tree from beetles. The spray is made up of Carbaryl (Sevin SL and XLR, and others), Permethrin (Astro, Dragnet, and others) and, bifenthrin (Onyx). Carbaryl is considered by the EPA to likely be carcinogenic to humans. It is moderately toxic to wild birds and partially to highly toxic to aquatic organisms. Permethrin is easily metabolized in mammalian livers so is less dangerous to humans. Birds are also practically not affected by permethrin. Negative effects can be seen in aquatic ecosystems as well as very toxic to other beneficial insects. Bifenthrin is moderately dangerous to mammals including humans. Bifenthrin is slightly more toxic to birds and aquatic ecosystems than permethrin, as well as extremely toxic to other beneficial insects.
Spraying is very effective at protecting the pines but is not recommended for large-scale use due to ecological and financial reasons. Pines should be sprayed before the beetle flight in July, so May or June will yield the best results. You can spray your own trees but this requires a great deal of spraying equipment and safety equipment. A licensed applicator is highly recommended.
Verbenone is the main compound for the anti-aggregate pheromone for the mountain pine beetle. This compound is produced by 3 companies: Contech, Synergy Semiochemicals Corp, and Hercon Environmental. Verbenone is a behavior modifying pheromone that tricks the pine beetle into believing that the tree is no longer useful to more beetles and they will leave the tree alone. Verbenone is useful in campsites and places close to creeks and rivers where spraying cannot be used. Verbenone does not kill the insects it simply pushes them away to another tree or area. It has been pretty successful in areas with low beetle populations but has not been very successful in areas with higher populations. Verbenone is only useful in small-scale operations.
Logs that are infested with beetle larva may be dealt with by burning, burying, chipping. They can also be dealt with using solar treatment. The solar treatment for killing pine beetle larva involves cutting and heating the logs containing the larva to 110 degrees F in or to kill the larva. There are 2 options when using solar treatment, with plastic and without plastic. This method takes 8 weeks and should be performed from mid April until early May, before the beetle flight. Logs with plastic cover will work better in slightly cooler climates. This method works well with a small number of logs in a high valued area.
The best and only long run defense against mountain pine beetles is to maintain a healthy forest. Cutting and thinning of overcrowded trees as well as an age and species diversification is helpful. This also helps to prevent hazardous forest fires.
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.
It is largely believed that 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. Some believe killing winter temperatures are becoming less common with global warming; a factor, when combined with increased summer thermal input, has resulted in a range expansion into Canadian boreal forests and increased activity in high-elevation whitebark pine forests (Logan and MacFarlane, Figure 2, http://www.actionbioscience.org/environment/loganmacfarlane.html)
The current outbreak of mountain pine beetles is ten times larger than previous outbreaks. Huge swaths of central British Columbia and parts of Alberta have been hit badly, with over 40 million acres (160,000 km2) of BC's forests affected. 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. In fact, there is evidence of higher beetle reproduction in naïve host tree populations. 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. 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). Predictions for 2008 suggested that over 2 million acres (8,100 km2) of trees would be killed by the beetle.
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.
A lodgepole pine tree with a pitch tube.
A lodgepole pine tree infested by the mountain pine beetle, with visible pitch tubes.
A pine tree forest north of Breckenridge, CO showing infestation in 2008. Currently, over 15 million hectares are either infected or destroyed by the mountain pine beetle.
Current legislation and other options
One of the options that many people have looked at is the above Integrated Pest Management or IPM. However, these often use very harsh chemicals that are hard on the environment. An alternative to these chemicals is thinning of the trees. Including the taking out of infected trees and reduction of current tree. Colorado’s forests are much more densely wooded making them much more susceptible to the beetles. Current legislation is in place to help with the growing beetle problem. Colorado Senators Mark Udall and Michael Bennet announced that Colorado will receive 30 million out of the 40 million dollars being diverted by the U.S. Forest Service to fight the millions of acres of damage caused by the mountain pine beetle in the Rocky Mountain Region.
Implications for the future
Some experts have predicted that if the issue is not eradicated, many of Colorado’s mature lodgepole pine forests will be killed within three to five years. Regeneration of decimated forests has begun as the US Forest Service hires loggers to remove the dead trees.
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.
Biofuel/Alternative Energy Production from Beetle Killed Trees
The huge number of beetle-killed trees poses a substantial risk of devastating forest fires. Forest thinning to mitigate fire danger is expensive and resource-intensive (Kumar 2009). Attention is turning to ways to turn this liability into a source of cellulosic biofuels.
Currently, biofuel production relies primarily on crops such as corn and switch-grass, thought to be worse for global climate change in the long run due to the cost and water demand associated with these types of agricultural products.(citation?) Ethanol may also be produced with waste products, a competitive option in the current market (Kumar 2009). The Mountain Pine Beetle epidemic has provided immense amounts of waste biomass that can be used for this purpose.
Leaders in western U.S. states and Canadian provinces have promoted legislation to provide incentives for companies using beetle-killed trees for biofuel or bio-power applications. Sellable commodities resulting from Mountain Pine Beetle damage can help subsidize the cost of forest thinning projects and support new job markets. Colorado's Department of Energy recently provided $30 million toward construction of the state's first cellulosic ethanol plant, to convert beetle kill into ethanol. Lignin, a byproduct of the process, can be sold for applications in lubricants and other goods (MacLachlan).
- 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.
- ^ a b http://www.csfs.colostate.edu/pages/documents/Thoughts_about_Verbenone_April_2009.pdf
- ^ a b http://www.csfs.colostate.edu/pages/documents/Thoughts_on_spraying_trees-version2_final_April_2009.pdf
- ^ http://www.csfs.colostate.edu/pages/mountain-pine-beetle.html
- ^ http://www.csfs.colostate.edu/pages/documents/Solar_Treatment_for_Mountain_Pine_Beetle_April_2009.pdf
- ^ 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.
- ^ "Mountain Pine Beetle - Ministry of Forests and Range - Province of British Columbia". http://www.for.gov.bc.ca/hfp/mountain_pine_beetle/facts.htm.
- ^ "Climate change and range expansion of an aggressive bark beetle: evidence of higher reproductive success in naïve host tree populations". doi:10.1111/j.1365-2664.2010.01848.x.
- ^ 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.
- ^ Robbins, Jim (2008-11-17). "Bark Beetles Kill Millions of Acres of Trees in West". The New York Times. http://www.nytimes.com/2008/11/18/science/18trees.html. Retrieved 2009-02-09.
- ^ Petit, Charles (2007-01-30). "In the Rockies, Pines Die and Bears Feel It". The New York Times. 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.
|Wikimedia Commons has media related to: Dendroctonus ponderosae|
- Death and Rebirth, Mountain Pine Beetle, Pesticides, Carcinogens, Cancer -David Chernoff, Manual For Living
- The Falldown Documentary- A look at the devastating impact of the beetle on British Columbia and Canada's Economy
- Trees targeted by beetle
- 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
Kumar A.. 2008. A conceptual comparison of bioenergy options for using mountain pine beetle infested wood in Western Canada. Bioresource Technology. [2008 July 9, cited 2008 April 2008] Vol. 100: 387-399.