Spruce bark beetles a danger to Alaskan spruce trees

WASILLA — The Mat-Su Valley – particularly Meadow Lakes and the Houston area – has been experiencing a significant rise in the infestation of spruce bark beetles recently, causing many locals to worry over the impending destruction of the beloved Alaskan spruce tree.

However, the death of the spruce trees is not something to be concerned about, according to Stephen Brown, the district agricultural agent for the Mat-Su/Copper River District of Alaska.

“Spruce bark beetles are actually an important part of the environment, though we don’t like it because it destroys our spruce trees,” said Brown, who also noted that the insect is native to Alaska.

The dead trees can provide a habitat for other wildlife, and recycle organic material back into the soil. The dying older trees thin out the forest so that younger trees, which are usually not touched by the beetle, can have room to grow up.

The biggest concern is that the sick trees create fuel for forest fires in the drier part of the summer, so people should be cutting down all spruce trees closer than 150 feet to their house whether the trees are infected or not.

Since the dry, dead wood is a great source of firewood, the best thing to do is to cut down, debark and burn any tree infested with beetles. This is especially important in the months of May, June and July as that is when the insects develop wings and fly around looking for other host trees.

When a tree is at the beginning of its infestation it will have sawdust around the base and will “pitch out” by focusing sap into the holes that the beetles have drilled in the bark.

An advanced infestation will cause the bark to come off the tree and the needles to turn brown.

Young spruce trees are rarely impacted by the beetle, and for healthy adult trees regular watering and fertilization can give them the ability to fight off the attack.

People can also cut off the bottom six feet of limbs as it confuses the beetle and they are less likely to infest the tree.

“The spruce bark beetles seem to know how to isolate out a weak tree, and those are the trees they attack first,” said Brown.

The beetles heavily attack the spruce trees like this about every thirty to fifty years, and Brown believes the last occurrence in the Valley was likely more than one hundred years ago. After the weaker trees have been cut down or eaten the beetle will gradually die off, leaving the younger forest room to grow.