Scientists are increasingly alarmed that global warming has removed any control that bitterly cold winters once had over the mountain pine beetle, which co-evolved with pine trees over millennia in the West.

This is umpteen article I’ve posted on the mountain pine beetle. I think the beetle, drought, heat and fire are doing just what we would expect in a warming world, reduce the acreage covered by forests  in the northerly and high elevation regions of the Earth.

I am still waiting for the explosion when the B.C. or Alberta beetle kill catches on fire. It covers many thousands of square miles.

Read “Insect Insurrection” by Brodie Farquhar. Casper Star Tribune.

About The Author

Ralph Maughan

Dr. Ralph Maughan is professor emeritus of political science at Idaho State University. He was a Western Watersheds Project Board Member off and on for many years, and was also its President for several years. For a long time he produced Ralph Maughan's Wolf Report. He was a founder of the Greater Yellowstone Coalition. He and Jackie Johnson Maughan wrote three editions of "Hiking Idaho." He also wrote "Beyond the Tetons" and "Backpacking Wyoming's Teton and Washakie Wilderness." He created and is the administrator of The Wildlife News.

9 Responses to Insect insurrection: On the explosion of the mountain pine beetle

  1. Robert Hoskins says:

    I have been cruising whitebark pine populations in the Upper Wind River Valley of northwestern Wyoming this summer looking for evidence of pine beetle infestation in this very important food source for grizzly bears. The news so far, although I still have another month of cruising before I have to go to fall hunting camp, is that some areas are devastated, while others have barely been invaded–yet. It appears that most of the lucky areas are on the periphery of the Greater Yellowstone Ecosystem, while whitebark pine populations at the center of the ecosystem are in big trouble, having been hit hard by pine beetles.

    Traditionally, the low temperatures of the high valleys and plateaus have generally kept the pine beetle out, but we are seeing much warmer temperatures at higher elevations and the pine beetle has been able to take advantage of that to move into whitebark pines throughout the ecosystem.

    The primary ecological effect is that a primary food source for grizzly bears is under threat. For this rreason, the bear should not have been delisted. The primary reason for my work this summer, and, if funding can be found, for next summer, is to locate areas in the Greater Yellowstone where whitebark pine are still healthy and can still provide pine nuts for grizzly bear consumption.

    What’s important about these peripheral areas and the status of whitebark pine in them is that all of these areas lie outside the federally designated Primary Conservation Area. In Wyoming, the G&F Dept. bear plan calls for managing bears at “low densities” in these areas that have become vitally important to bears, since food sources like whitebark pine are in such bad shape within the PCA.

    Rather, these peripheal areas outside the PCA need to be opened up to bear occupancy because they are important to short, mid, and long term survival of the bear.

    Those of us working on this project hope to put together a map of suitable habitat for grizzly bears outside the PCA to change the boundaries, or better yet, eliminate the boundaries, of the PCA. Wherever habitat exists, bears need to be allowed to occupy it at whatever densities the bears decide is appropriate.

    By the way Ralph, have you noticed how this writing box bleeds over into the right hand column of the page? That makes it hard to edit what is written. Is there any way to fix this problem? The initial version of this web page was much better for making comments than what you have now.

  2. It’s plain to anyone with long experience in Yellowstone Park and the surrounding area that it is much hotter in the summer now, and warmer in the winter too (talk to snow groomers for the snowmobiles).

    I imagine the grizzlies are stressed at all elevations this year. A week ago I noticed the berries were drying up in areas adjacent to the Park (to the west) where thimbleberries grow, and with the decline of whitebark pine the bears will have less even if it is a productive year for the those whitebark that are still alive.

    I’ve long argued that the most critical country for grizzly bears is south of the Park in Wyoming. Let’s hope the lawsuit ending the delisting is successful because the argument (incorporated in the lawsuit) that US Fish and Willdlife Service failed to account for an adverse climate change is obvious. It is already here.

  3. Jeff says:

    I was under in the impression that pine beetle mainly hit lodgepole pine and the blister rust was the threat to whitebark pine. I recently visited a friend near Granby, Colorado on the westside of Rocky Mountain National Park. Even though I use to live down there and knew of the bug kill, I was utterly stunned by the scope and depth of beetle kill. Beginning just south of Saratoga, WY on the eastern flank of the Sierra Madre all the way over to Granby down to Winter Park entire hillsides for miles and miles rust red colored evergreens is all one can see. The liklihood of an absolutely devastaing wildfire is unavoidable at this point. My wife asked whether or not it was a threat to NW Wyoming’s forest and I said I didn’t think so right now…I guess I was being naively optimistic.

  4. Robert Hoskins says:


    Unfortunately, the whitebark pine is experiencing a double whammy–the exotic blister rust and the pine beetle. The pines of NW Wyoming are in trouble.

    The pine beetle issue is that after all the whitebark pine is a pine tree, and the same beetles that are hitting lodgepole at lower elevations are also getting into whitebark pine. As the climate is warming up, whitebarks are no longer able to depend upon the extreme extended cold temperatures (minus 40-50 degrees F) that “normally” mark alpine ecosystems and historically have kept the pine beetle out of the higher elevations and thus out of the whitebark pine.

    In the 1920s, there was a warm period that allowed pine beetles to infest Rocky Mtn whitebark pine, and many forests were devastated through the 1930s. These forests are referred to in the literature as “ghost forests.” We are now seeing the same problem with warming in whitebark pine of the Greater Yellowstone. With global warming, we are not seeing the rough, cold winters at high elevations that we had historically, and whitebark pine is dying at alarming rates from beetle infestation. If you drive on highway 26 over Togwotee Pass from Dubois going down into Jackson Hole/Grand Teton National Park, for example, the devastation is visible from the road–red all the way.

    Whitebark pine do respond to pine beetle infestation as do other pines, by attempting to flood out the pine beetles with pitch. I have seen this phenomenon during my survey this summer; what you see are numerous “pitch tubes” or “pitch plugs” in the bark of the tree, where pitch has copiously flowed out of the holes bored in the bark by the beetles. The problem is, if there is a “flood” of pine beetles, the normal defensive mechanism is overwhelmed. And that’s what we’ve got, as the warmer temperatures have also speeded up beetle reproduction and we literally have swarms of beetles.

    We also have the problem of the history of fire suppression, resulting in many old trees in the population that cannot respond to infestation as can younger trees. And, with the warmer temperatures, not to mention the drought, the trees are already stressed, even the younger ones, which also limits their ability to defend against beetle infestation.

    From the bear’s perspective, it is the mature trees that produce the cones in numbers large enough to provide sustenance and the high calories needed for them to go into their dens in late fall. The cones are harvested by red squirrels and cached in the middens, and the bears raid the middens. A midden raided by a grizzly bear looks like a shell hole from the Western Front during WWI.

    On the other hand, in the peripheral (to the bear primary conservation area) areas, I am seeing good whitebark regeneration.

    So, yes, it’s devastating. Blister rust both kills and lowers a tree’s resistance to pine beetles. Given the slow growth periods for whitebark pine at high elevation, not to mention the length of time necessary for a tree to mature and produce cones and seeds (c. 50 years), things are not looking good either for the trees or the bears. There is some research going on to find trees that may be genetically resistant to blister rust, and to collect seeds from same for replanting, but as yet there is no real defense against the pine beetles as long as temperatures remain too high. We need some damn cold winters.

    Hope this is informative.


  5. Vicki says:

    I camp nearly every weee in the North Park area. Each year the redness is increasing. This sprig there was a huge windstorm (one enormous gust actually). The number of tress, young and old, that were uprooted or snapped in pieces is just incredible. I don’t a whole lot about pine beetles, but I have had several of them land on my shirt at once. Do they eat only green trees? Or do they eat uprooted ones too? I know that they have made the entire mountain range around North Park a giant box of kindling (sp?).

  6. Vicki says:

    Sorry about the previous typo’s—bumpy ride.

  7. Tim Z. says:

    I was camping last weekend near Stanley and it’s getting really bad there also. I camp near Beaver Creek and it seems it’s getting worse by the week. I don’t see how they could ever begin to surpress a fire there.

  8. Robert Hoskins says:

    To answer an above question, beetles require living trees to complete their life cycle.

  9. HikerIL says:

    Last year, near Old Faithful in Yellfowstone Park, an Asian Longhorn Beetle landing on my shirt. The city of Chicago and some suburbs have cut down thousands of trees to control this menace… Very depressing.



‎"At some point we must draw a line across the ground of our home and our being, drive a spear into the land and say to the bulldozers, earthmovers, government and corporations, “thus far and no further.” If we do not, we shall later feel, instead of pride, the regret of Thoreau, that good but overly-bookish man, who wrote, near the end of his life, “If I repent of anything it is likely to be my good behaviour."

~ Edward Abbey