Prevention & Management

Prevention

Much research is being conducted to find an effective solution for preventing the propagation of mountain pine beetles.  One method involves removing older, weaker trees in a group of trees to increase the space between individual trees.  It is hypothesized that by removing some trees, the remaining trees will have more access to light, nutrients, and water and perhaps make the trees hardier and more prepared to withstand beetle attacks (Dept. of Natural Resources, Montana).

Another possible method involves pheromones.  Previously, it was detailed that beetles signal to one another by emitting certain types of pheromones depending on the situation.  Verbenone, has been sprayed on trees to trick mountain pine beetles into believing that possible host trees are full of beetles thereby preventing beetle infestation (Dept. of Natural Resources, Montana).

Application of spray in the Bitterroot National Forest
(Courtesy of KYLQ)

Spraying other types of chemicals onto the trees to prevent mountain pine beetle infestations has also been put into use in forests.  The sprays are applied on healthy, high value trees during early summer and reapplied once a year.  Chemicals that have been used include: carbaryl, permethrin, and bifenthrin.  Sprays vary in their protectiveness depending on how they thoroughly they are applied.  If sprays are applied to the wrong trees, the spray will not be effective.  If the sprays are not applied thoroughly, beetles may not be affected and still enter the tree.  If the spray concentration is not strong enough, then beetles may not be deterred.  Therefore, thorough application of sprays and other preventative methods are of the utmost importance (Colorado State University).

Management

Unfortunately, prevention is not always enough to stave off further intrusion of organisms.  Lack of manpower to carry out prevention techniques is one of the many reasons why beetles can propagate without much impediment.  Therefore, methods to control mountain pine beetle infestations have been designed.  One method involves manually peeling bark off of infested trees.  Lack of bark allows for air to enter the pitch tubes which leads to desiccation and the eventual death of beetles.  The wood is burned to eliminate any trace of mountain pine beetle, buried under a large amount of soil, or removed from the site to prevent emergence of any beetles.  A downside to this method is the sheer amount of manpower necessary to carry out the task of manually pulling bark off of thousands of trees (Colorado State University, Dept. of Natural Resources, Montana).

Naturally occurring controls also exist that can limit beetle propagation.  Predation of mountain pine beetles is one such control.  Woodpeckers and some other insects consume the beetles and can help keep beetle populations low (Colorado State University).

Recommendations

The prevention and management techniques listed vary in their effectiveness.  In fact, there is no standard method for limiting duration and magnitude of mountain pine beetle epidemics (Frost 2011).  Further research into possible suppression techniques is highly recommended.  Specifically, large scale suppression techniques should be emphasized because of limited manpower.