Driving through the Rocky Mountains on our recent vacation, a little voice from the backseat spoke up to ask “Momma, what killed all those trees?" In his short life, I'm sure my 6 year old had never seen an entire hillside devastated by the loss of nearly every tree. It soon became apparent that my husband and I would need to come up with a real reason for this devastation or endure many more hours, if not days, of hearing the question voiced over and over.
The area we were in at the time was in northern Colorado. All those dying and dead trees were actually victims of a little (7 mm long) insect called the Mountain Pine Beetle. This immediately caught the interest of my other son, the 7 year old aspiring entomologist and so began our education on the Mountain Pine Beetle.
It seems this little bug bores into trees to lay its eggs. Not surprising, as many insects do the same thing. In response to the invasion a tree will increase its production of sap to try to dissuade the little pest from burrowing in. The Mountain Pine Beetle however, is a carrier of the spores of a deadly blue-stain fungus. As she burrows into the tree, these spores come off her onto the tree and find a new home where they can grow. The spores choke off the vessels of the tree in the sap and inner layers and ultimately cause the tree to die by restricting the trees vessels’ ability to carry water and nutrients.
The Beetle starts out by moving into trees that may be weakened by various factors including lightning, old age, or drought. After the beetle has established itself though the population grows and the beetle begins to move into larger, healthy trees, going from tree to tree until the majority of the trees in an area are affected.
We noticed the damage from the beetle in Colorado, however, the outbreak is not limited to there and so far millions of acres have also been lost in Montana, British Columbia and Alberta. How it will eventually end remains to be seen at this time. Extreme cold winter temperatures may help to kill off the larvae of the beetle and reduce it's reach the following year. People are trying to help control the infestation by removing and burning dead or infected trees. Some are trying to slow the spread of the beetle by covering their dead fall trees with plastic or using sprays to kill the larvae. Controlled burns are another option. In populated areas, however, it is difficult to even do a controlled burn without threatening homes. By everyone's guess, this outbreak is not over and it still remains to be seen how many millions of acres of trees will ultimately be killed.
Laura Beth writes on various current issues. You can view more about the Mountain Pine Beetle and other invasive insects at her blog at http://www.deadlytreeinsects.blogspot.com .