An unreleased study on Montana's forest has some good news when it comes to western pine beetle infestation.

United States Forest Service Forest Health Protection Group Leader Greg DeNitto says pine beetles appear to be in decline. "What we're all seeing is a decline of the number of acres that are infected and the intensity and severity of that infestation in most areas."

In 2012 researchers calculated the pine beetle infestation at around 600,000 acres compared to a little over a million acres in 2011. The aerial surveys aren't entirely reliable because variables such as too much smoke and different flight patterns can throw off the studies, but DeNitto says the trend has been consistent for the past three years.

There are still a few places where pine beetles are making headway. "The areas that are most active right now are the Big Hole area, out of Wisdom and over towards Chief Joseph, Lost Pass trail area and the southern end of the Bitterroot range," DeNitto said.

Greg DeNitto:

It appears the decrease is caused in part by the fact that pine beetles have nearly eaten themselves out of house and home. The lack of susceptible trees combined with some deep freezes in past years have helped decrease beetle kill.

DeNitto says another forest pest is on the rise and estimates that the western spruce bud-worm can now be found on nearly one million acres of Montana forests.

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