It has been said that an ounce of prevention is worth a pound of cure. There is no substitute for good health. This is true of our forest. Forest Management is that ounce of prevention that will keep forests healthy and growing without the burden of a pound of cure. Proper forest management and maintenance yields forest health, which provides a stronger base if a mountain pine beetle epidemic should occur.

A managed stand of ponderosa pine in Browns Creek area.

A thinned area near Eddy Creek. Thinning reduces MPB and prevents wildfires.

Near Three Mile Creek. An example of trees that have died as a result of the MPB.

Managed forests are healthy forests producing unlimited benefits such as: reduced wild land fire, visual appeal, improved elk/deer habitat and of course healthier trees.
The managed ponderosa pine stands of Browns and Eddy Creek of the Salida Ranger District, San Isabel National Forest are examples of effective forest management. Recent aerial photography of 1998 shows these areas to be minimally impacted by the mountain pine beetle when compared to unmanaged areas, which were highly impacted.
The Eddy Creek area was harvested and treated from 1990 to 1993 using primarily a sanitation/salvage cut. The results seven to eight years later show a majority of the trees are healthy with a reduced susceptibility to the mountain pine beetle.
Research indicates there are certain stand characteristics that relate to susceptibility to beetles. By managing today we can sustain tomorrow's forest health.

Q & A

Did the recent cold weather kill the beetles and end the epidemic?

It depends. MPB produce its own "anti-freeze" compounds that protect it from all but the coldest weather.
If the below-the-bark temp. reaches -4 F for a few consecutuve days, the beetles may be killed.

Preventative Spraying

How do I decide whether I should have my trees preventatively sprayed?
First of all, there should be a local threat of MPB attack. It makes little sense to "immunize" trees against a threat that doesn't exist at present. A good rule of thumb is that if red, beetle-killed trees exist within sight of the trees being considered for treatment, a threat exists.
Second, the trees being considered should be big enough to be attacked. That is, they should be at least 8 inches in diameter at eye level. Smaller trees are occasionally attacked, but preventively spraying 6 or 7-inch trees is just not worth the low risk of attack. Thirdly, the trees being considered should be of high-value.
Fourth, how much do you want to spend and what price has been quoted?
Other considerations exist. If a tree has been unsuccessfully attacked during recent beetle flights (within the last two or three years), then it is quite likely this same tree will be revisited during subsequent flights. There is something about it the beetles like and they will continue to attack until the tree is no longer able to fend for itself by pitching them out.

Saving a high-value tree. Preventative spraying is not intended for use on every tree in the forest.

Trees that have been injured by lightning, construction, below ground lines, soil filling or compaction and other insults prior to beetle flight are prone to attack. So are trees heavily infested with dwarf mistletoe and those which have been recently pruned.
The cost of having trees sprayed varies by the company, the distance of the trees from the contractor's base, the number of trees to be sprayed, and the size of the trees. However, an "average" susceptible pine (14" diameter and 45 feet tall) should cost in the range of $10 to $25. Trees need to be treated only once per year (treatments for minor bark beetles like ips and twig beetles which have more than one generation per year and which can attack branches in the outer tree crown may require two treatments per year (April and July).
There is some evidence that lodgepole pines at high elevation may only need treatment once every other year, but to be safe, annual applications are recommended.
If you have your trees sprayed you do not need to leave the area. If you are in the house when spraying is occurring, close the windows and turn off the air-conditioner or other devices that might draw in outside air.
During non-rainy weather, preventive spray dries within two hours of application. After this time, normal activity can resume. Just to be safe, children and pets should be kept out of the area for this period, also. Anyone with known chemical allergies or sensitivity, should consult with their physician prior to arranging for spraying.
Ask the company doing the work to provide a label or Material Data Safety Sheet for the chemical they intend to use.
You can apply preventative spray yourself if you can reach high enough, apply it to all sides of the tree trunk, and ensure your safety against falls and inadvertent spraying.
All of the above can be accomplished by using a stepladder, a small pump-up hand sprayer, goggles, gloves, hat and perhaps an apron.

Q & A

Does preventative spray harm birds?

We should never say never when it come to pesticides, but evidence over the past 20+ years suggests that the materials approved for this purpose have negligible impact on birds when applied the way the label stipulates.

Q & A

Are MPB attracted to fresh-cutting activity?

Normal recommendation is to suspend all cutting "immediately prior and during" the expected flight of the beetle. Allow up to a month for fresh cuts to dry prior to the flight of the MPB.
Cutting should not be done during the actual flight period of July 15 to September 15.

Forest and the Passage of Time

By closely observing the forests which surround Salida, we can decipher the history of these lands. The condition of the forest tells the story not only of the trees that are here now, but allows us to reconstruct what happened long before the current trees sprouted.
One artifact of time is the assemblage of plants that comprise the forest. The conifers are a very ancient group having arisen over 300 million years ago; they shared the landscape with the dinosaurs. The flowering plants came later, evolving over 120 million years ago. These plants have formed a basis for life that has been depended upon by animal life for eons.
The relationship between pine beetles and pine trees is an ancient one, and has been shaped and refined for at least 215 million years.

Aerial photo of a heavily-infested dense stand of ponderosa pine trees.

Infested hillside of ponderosa pine, showing large groups of dead trees that are the result of at least three years of attack. Some of the unattacked area may contain trees not big enough to support MPB.

An important component of the pre-historic order was the coming of humans into North America. Even as the glaciers of the last ice age were retreating northward, the land around us served the native population that lived here by providing food items, materials for shelter and all the other necessities of life.
The native peoples managed these lands, mainly through the use of fire, to alter the landscape to suit their needs. The natives used fire to promote desired plants for food and medicine, to clear land and provide forage for game and many other functions.
The coming of Europeans to the central Rockies brought many changes, both social and ecological. Consider the fur trappers who came to these mountains to gather beaver pelts early in the 1800's. Although their numbers were very limited, their activities had great impact on the streams and forests of the region as they removed beavers from the ecosystem.
The trappers were followed in turn by miners, cattlemen and the railroad. All of these groups exerted great change upon the forest landscape. Wood was sought as a necessary raw material to support these activities. By the turn of the century, the forests of the central Rockies probably contained the least biomass since the Ice Age.

A "healthy looking" ponderosa pine. This is the appearance of a MPB infested tree in fall, winter, or spring prior to fading.

There are many important tools in reconstructing an image of what these forests looked like in the past.
Dendrochronology is the technique of using tree rings to calculate the rate at which trees grew in the past. Dendrochronology studies have been used to determine old weather patterns, document the occurrence of insect outbreaks and calculate fire intervals. Fire history is also determined by soil analysis, layers of ash at varying depths can determine ancient fire regimes.
A method of determining change since the coming of Europeans to North America is the use of change photography. There is a surprisingly large body of images that record the condition of the land from the very early days of entry into the Rocky Mountain region. These photographs can be compared to current depictions of the same sites, thus documenting the changes from previous times to the present.
In nearly all of the change photography studies from this region, the results have shown that the forests of today are denser, older and contain more biomass than they have in over 100 years.

Q & A

What types of trees does the MPB attack?

MPB normally attacks ponderosa, lodgepole, and limber Pine.
Scots, austrian, pinyon, and douglas-fir have been attacked during special circumstances.

Q & A

Are MPB attracted to fresh-cutting activity?

Normal recommendation is to suspend all cutting "immediately prior and during" the expected flight of the beetle. Allow up to a month for fresh cuts to dry prior to the flight of the MPB.
Cutting should not be done during the actual flight period of July 15 to September 15.

Controlling the Mountain Pine Beetle

They're back! The mountain pine beetle (MPB) Dendroctonus ponderosae, which was responsible for the death of two million Colorado trees during the late 1970s is making a comeback. This is no surprise to foresters in the Rocky Mountains who have experienced the cyclic nature of such infestations every 20 - 30 years. Colorado is in a period of population buildup and can expect to lose trees numbering in the hundreds of thousands to this insect over the next 5-7 years.
Mountain pine beetles develop in pines, particularly ponderosa, lodgepole, scots (scotch) and limber pines. Bristlecone and pinyon pine are less commonly attacked. During early stages of an outbreak the insects attack trees weakened through stress. Common stress factors are construction damage, over crowded stands, fire damage, mistletoe infection and old age. Once populations increase to epidemic levels, MPB may strike any of their favorite pines with a preference for the larger diameter trees

During the month of June the Colorado State Forest Service (CSFS) is flooded with calls concerning MPB. Around this time landowners notice their trees turning red. It seems to happen over-night. One day it is green the next red. While it actually doesn't happen this quickly, it is a relatively fast transition. The process that causes this "fading" actually began the previous summer.
MPB have a one-year life cycle in Colorado. In mid to late summer adult beetles emerge from the red-needle infested trees and fly to new green trees. With a successful attack the numerous beetles tunnel under the bark where they mate and the females lay eggs along a vertical gallery. These eggs hatch into larvae and feed on the inner bark growing larger during the next few months. In early summer, of the following year, the larva pupate into adults and the cycle continues.
The adult beetles carry fungi spores into the tree. The mutual network of beetle galleries and fungi blocking water and nutrient transportation through the tree rapidly starves the tree. This is why the tree turns red so quickly in early summer.
Left unchecked MPB can kill large patches of trees. While this is a natural occurrence few landowners enjoy losing the majority of their trees.
With the suppression of natural disturbances such as fire in the forest ecosystems, bug populations have become more destructive and occur more frequently.
The best control for MPB is a healthy forest. A healthy pine forest in Colorado generally has well spaced trees that are free of serious disease problems. Crowded conditions create stress in the trees as they compete for sunlight and nutrients. In many cases trees need to be thinned to achieve a well-spaced condition.
There are preventative sprays available for high value trees. Both carbaryl (Sevin®) and permethrin (Astro®) are registered to prevent beetle attacks. The spray is applied to the trunk in early summer to deter beetles from boring into the tree.
Many tree service companies perform preventative spraying for landowners. Forested subdivisions would benefit by organizing property owners to have their trees sprayed by the same company.
Inspect your trees as soon as possible! If you suspect they have successfully been attacked, contact your local Colorado State Forest Service office. They have several good publications that explain what to look for and how to take care of your infested trees.
If you start your treatment in the fall, you may have many more options available. If you wait until the trees fade the following summer your treatment options are limited. Trees left untreated can produce enough adult beetles to successfully attack 2 -3 new trees.
A healthy forest is no accident! Caring for your forestland takes time and effort. The Colorado State Forest Service is available to help keep your trees green and healthy.

Methods for Treating Infested Trees

• Treating individual trees infested with MPB is a labor-intensive task.
• The tree must be cut, the limbs removed and one of several treatments performed.
  
  Burning the log (preferably in a fireplace or stove.) 100% effective before July.
• Debarking the log, 100% effective before July.
• Burying the log. 100% effective before July.
• Haul to a "safe site" a mile or more from any pine trees. 90% effective.
• Solar drying the log 50-75% effective if done properly.
  

Credits:
Special Thanks to - Paul Janzen, Kathryn Hardgrave, Charlie Medina, Butch Butler, Monica Mellaci, Deanne Williams, Don McLaughlin, Larry Walker, Mark Thomas, Sam Schroeder, Tim Benedict, Barbara Timock, Tom Eager, Roy Mask, Dave Leatherman, Jim Cunio,
Bob Post, Cecilia McNicoll

Printing and Distribution - Arkansas Valley Publishing Company
Design - Greater Arkansas River Nature Association
Website - Mark Wiard