PIERRE - Trees infested by mountain pine beetles produce lumber that has the same structural integrity and durability as wood from non-infested trees, according to South Dakota forestry officials.
The blue-colored portions common in beetle-infested lumber are caused by a fungus carried on the beetles, but the interesting coloration does not affect the lumber, said State Forester Ray Sowers Sowers. And of course, it is harmless to your health.
The blue stain is created by a fungus, but it will not spread to other lumber. The lumber does not decay any faster than un-stained wood and will not cause mold.
As mountain pine beetles emerge from dead trees and fly to new green trees each summer, the pests carry the blue-stain fungus with them. As part of forest sanitation efforts, local sawmills and wood processors remove the green-infested trees and process them into boards. Removing green-infested trees before they die saves another five to eight additional trees that would eventually become infested the following year. When the trees are processed into boards, the resulting lumber has varying degrees of the blue-stain fungus throughout.
Some consumers shy away from these boards over concern of rot, mold, or other decay, which simply isn't true, explained Tom Shaffer, Chief Operating Officer with Neiman Enterprises, a forest products company. The structural integrity and lifespan of these boards is identical to those with no blue-stain.
Tom Troxel of the Black Hills Forest Resource Association, an industry trade association, said blue-stained boards are viewed as less desirable by the public, so the grading system reflects it.
Sawmills have the same harvest, hauling, and processing costs as an un-infested tree, yet the blue-stained boards are typically deducted one grade when they are finished, resulting in lower market value, Troxel said.
South Dakota Agriculture Secretary Walt Bones urges consumers and contractors to purchase blue-stained boards at the lumberyard because currently, many lumber-worthy trees are cut, chunked, and left in the forest because there's no market for the lumber.
Buying blue-stained lumber also helps forest managers in the fight against the mountain pine beetle, Bones added.