The Mountain Pine Beetle - still a problem.
The Mountain Pine Beetle adds another casualty to its list. Have a look at the tree stump in the center image above. Notice the bluish bands penetrating the log from the outside edge. That is the fungus associated with the Mountain Pine Beetle (MPB). There is a symbiotic relationship between the two organisms. Pine trees produce a thick resin (top image) which thwarts pine beetle infestation. The beetle carries the fungus on its mouthparts; when it attacks a tree the fungus is released and parasitizes the tree, growing ever inward over time. The beetle benefits from this because the fungus reduces the resin production by the tree allowing the beetle to attack it without mercy. The fungus benefits because it is given the opportunity to grow and obtain energy from the tree's tissues. The tree dies because the MPB drills pathways called galleries in the cambium layer. This is the thin layer just underneath the bark which the tree use...