LARAMIE -- A "perfect storm" of warmer winters leading to greater larvae survival, extended drought and extensive stands of older, more vulnerable trees has caused the pine bark beetle epidemic in northern Colorado and southern Wyoming, panelists at the University of Wyoming agreed Tuesday.

The panelists also seemed to agree there is no way to stop it.

Steve Currey, the Medicine Bow National Forest's director of renewable resources, told an audience at the UW College of Law that the forest lands affected by the epidemic in the eastern Snowy Range had quadrupled to nearly 100,000 acres from 2007 to 2008. He said it had gone from 223,000 to 347,000 acres in the western Snowy Range and the Sierra Madre Mountains in southern Carbon County.

The full epidemic has not yet hit the Pole Mountain and Laramie Peak areas, where there are more ponderosa pine among the lodgepoles, Currey said. But he saw no reason those areas will not be overcome during the next couple of years.

"These beetles can also infest ponderosas," he said.

Even smaller, younger lodgepoles that normally are more resistant to the insects are falling prey, he said.

Currey acknowledged that one reason the forests "are more mature and somewhat less healthy is due to the good job the Forest Service has done over the past 100 years in fire suppression."

Currey said the Forest Service is concerned that the widespread death of lodgepole pine trees could lead to more fires that threaten homes, power lines and other property. He said the agency is concentrating its limited resources at present on removing dangerous trees from roads, trails, campgrounds and power lines.

"You can understand that trees falling across a power line creates a danger of fire," he said.

So far, the Forest Service has attended to only 10 percent of the roadways that need to have dead trees cut down, he added.

The spraying of trees is effective for saving low numbers of important individual trees but is too expensive to employ over large areas, Currey said.

Dan Tinker, a UW botany and ecology professor, said the pine bark beetles are native to the ecosystem, not some introduced pest. He said scientists have been unable to determine if such a widespread beetle outbreak has occurred previously in these forests over thousands of years.

"But we do know there hasn't been anything like this in the past 100 years," he said.

Duane Short, a zoologist and activist for Biodiversity Conservation Alliance in Laramie, said decision-makers should not "put on blinders" and ignore the complex relationships that are at stake when actions are taken to address the epidemic. Short said that clear-cutting trees in the interior forests will have an adverse effect on wildlife such as martens, voles and goshawks and will do little to limit the spread of beetles or wildfires.

"Environmental factors are more responsible for beetle outbreaks and wildfire intensity than whether an area has been logged," he said. In fact, clear-cuts can create turbulent air flow which facilitates the injection of firebrands into the airstream, he said.

Deryl Woirhaye, who owns a home in the Wold Tract near Foxpark, said he and his neighbors have been asking the Forest Service for eight years to clean up the fuels near their subdivision.

Woirhaye said the Forest Service has twice told them the Wold project was on a schedule of upcoming work, but then was dropped.

They had to contact Wyoming's representative in Congress to get some attention, he said.