Beetles Continue to Ravage Drought-Stressed Pines

GLENWOOD SPRINGS, Colo. -- The tiny Ips beetles that have ravaged forests throughout the state continue to burrow their way into valley pines.

"The population of bugs are going up - there's lot of food up the Roaring Fork Valley," said Kelly Rogers, assistant district forester for the Colorado State Forest Service in Grand Junction. "We're anticipating more activity and more impacts on the landscape out there."

The small insect, less than an inch long, attacks weakened pine trees by developing under the bark and cutting off the sap flow from the roots, said Scott Formby, forester for the state forest service. In the juniper and piñon pine woodlands of the Roaring Fork Valley, the beetles have settled into the pines crippled by the six-year drought.

The beetles, which evolved with the trees, proliferate under drought conditions when the trees can't adequately defend themselves against attack, Rogers said.

The worst infestation has occurred in the Four Corners area, where the tiny beetles have decimated nearly 80 percent of the pines, according to the 2003 Report on the Health of Colorado's Forests.

The Roaring Fork Valley's elevation may become its "saving grace" against a similar infestation - piñons, and therefore Ips beetles, predominate in wetter areas of higher elevations, such as in the Four Corners area, Rogers said. Much of the Roaring Fork Valley is covered in a mixed oakbrush and juniper woodland type, without many areas of widespread piñon.

But certain regions in the valley do have pure piñon stands, such as the red hills north of Carbondale, said Winslow Robertson, a fire ecologist for the Bureau of Land Management's Grand Junction and Glenwood Springs field offices.

"I've got some real concerns in the Roaring Fork, especially these stands that are predominately piñon," Robertson said.

The first sign of an infestation appears in pitch tubes of sap that look like "little pieces of bubble gum" all over the tree trunk, an effort by the tree to push the insects out, Formby said. Once the beetle has bored in, fine sawdust - boring dust - will be deposited around the tree. In a few months, the tree will begin to fade, the needles will go brown, and then "the tree is history," said Rich Edwards, co-owner of Fire Ready, a wildfire mitigation company in Glenwood Springs.

The beetle infestation poses a dilemma for fire ecologists, since their presence can both reduce and add to wildfire hazards. The dead needles of the pines, which can stay on the tree for up to two years and provide more fuel in the case of a wildfire, is a short-term hazard. However, after the needles drop, the dead wood, in its vertical position, will limit the spread of a fire, according to Robertson. In addition, in a post-fire environment, pines become weakened, providing an ideal state for the beetles to multiply. For example, at the site of the Coal Seam Fire, the Ips beetle has affected several pines, Rogers said.

Wood pieces left on properties following wildfire mitigation can also contribute to beetle populations, since the beetles like the freshly-cut wood, Edwards of Fire Ready said. The solution has become a bit of a controversy for foresters and officials, but many have agreed that protecting against wildfire trumps the beetles, Edwards said.

"We're trying to get more fuel projects implemented on the ground, but now Mother Nature's throwing us a curve ball," Robertson said.

In his wildfire mitigation projects, Edwards has remedied the problem by blowing wood chips away from other pines, so that the beetles can't spread to new trees.

Controlling the beetle boom has proven difficult for forestry officials. In times of low infestations, birds such as woodpeckers and flickers will eat the beetles, but when the beetles explode in population, they alone can't control the insects.

Landowners with infected trees have a few options: they can kill the beetles using insecticides such as permethrin or carbaryl, or remove the tree altogether.

Eileen Coch, a resident of Elk Creek subdivision near New Castle, had her husband cut down two beetle-infested piñons on her family's property last year.

"When you live in a subdivision where you crave privacy, your trees are very valuable," Coch said, adding that their absence has left a gap where she can see her neighbor's cars. The state forest service recommended that Coch remove the trees to prevent the beetle spreading to her other seven piñons.

Efforts are underway to assess exactly how many trees in the valley and throughout the state suffer from the Ips beetle. In August or September, the U.S. Forest Service will conduct an aerial insect disease survey with assistance from the state forest service, Rogers said.

Although the beetles sometimes go through intense population cycles, they have always been a part of nature in the valley. But the high density of trees in the valley, due to decades of fire suppression practices, is not so natural.

"Not many people like to hear this, but there's way too many trees out there," Edwards said. "It's just optimal conditions with so many pinions getting stressed with drought. It's a perfect formula."