Is it mountain pine beetle or autumn needle shedding?
All of these symptoms can be confused with autumn needle shedding, sometimes referred to as needlecast, which occurs annually in some evergreens. This is the tree’s natural process of shedding the older needles in the fall and is part of the annual growth cycle. Dying needles undergoing this process generally are clean and closest to the trunk, whereas beetle-infested trees may turn an off-shade of green, or start to turn brown at the bottom and proceed up the tree.
