Pine Beetles Feeding On Legacy Of Ice Storm

Walking through the Dishman Hills Natural Area, Guy Gifford sees the ghosts of Ice Storm.

Here and there, ponderosa pines are turning yellow. About 60 have shown up so far.

Gifford, a stewardship forester for the state Department of Natural Resources, sees even worse damage in the Pinecroft Natural Area Preserve. There, just west of the old Walk in the Wild zoo site, about 100 ponderosa pines are fading.

The trees’ killers - tiny pine engraver beetles - were strengthened this year by the abundant slash left behind by Ice Storm. Only now, long after the beetles have left, are property owners seeing the damage.

“We’ve been concerned about this all summer,” Gifford said. “In May, the beetles started breeding like crazy.”

Pine engraver beetles, known as ips beetles, have been an ongoing concern throughout Eastern Washington. They hibernate each winter, waking up weak and hungry in the spring. And their favorite food is pine slash.

Most years, slash is sparse enough to allow just 10 to 15 percent of the beetle population to survive.

“Last spring, there was so much slash everywhere, almost all of them survived,” said Ladd Livingston, a forest entomologist with the Idaho Department of Lands.

As a result, pine trees, especially ponderosa pines, faced a higher risk of being attacked. Weak trees - those in dense stands or in areas without sufficient moisture - were the prime targets.

Pines that succumbed to this year’s early generations of the beetle are just now starting to turn yellow. Those attacked by later generations may not show any signs until spring, Gifford said.

By the time the tree turns yellow, the beetles have already moved on, he said. Letting the tree stand won’t put surrounding trees at risk. Property owners can either cut it for the wood or leave it as wildlife habitat.

The trees will eventually turn burnt orange and red in color.

Although it’s too late to save trees already hit by ips beetles, property owners can prevent future damage by:

Thinning overly dense stands of trees.

Removing new slash as soon as possible. Slash that has been on the ground more than six months no longer attracts beetles.

Keeping trees adequately watered and fertilized. Deep irrigation is especially important in late fall.

, DataTimes MEMO: This sidebar appeared with the story: PINE PROBLEMS? Property owners with questions about how to deal with bark beetles or dead trees can contact Guy Gifford at the state Department of Natural Resources by calling 1-800-527-3305, ext. 116. A DNR stewardship forester can provide free site visits to property owners with pine stands of at least five acres. Owners with fewer trees can have their questions answered over the phone.