Colorado Pine Beetle

Keystone Pine Beetle




The brown trees in the above pictures were caused by the pine beetle….

The beetles kill the 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, and produce pheromones which attract other beetles and results in mass attack. The trees respond to attack by increasing their resin output in order to discourage or kill the beetles, but the beetles carry blue stain fungi which, if established, will block the tree resin response. Over time (usually within 2 weeks of attack), the trees are overwhelmed as the phloem layer is damaged enough to cut off the flow of water and nutrients. In the end, the trees starve to death, and the damage can be easily seen from the air in the form of reddened needles. Entire groves of trees after an outbreak will appear reddish for this reason. Usually, the older trees die first. After particularly long and hot summers, the mountain pine beetle population can increase dramatically, which leads to the deforestation of large areas. Current outbreaks are in Rocky Mountain National Park.

The current pine beetle outbreak may be the largest forest insect blight ever seen in North America.

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.

If you have additional information regarding the Pine Beetle please feel free to post……

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