The mountain pine beetle epidemic has run its course in the Colorado high country, but there’s a new bug on the rise. Spruce beetles have killed huge swaths of mature spruce beetles in southwestern Colorado, especially on the Rio Grande National Forest — and they appear to be moving north.

In another Science Daily article, new research indicates that a combination of drought and mountain pine beetle attacks are the primary forces that have killed more than 2.5 million acres of

New research concludes that a one-two punch of drought and mountain pine beetle attacks are the primary forces that have killed more than 2.5 million acres of pinyon pine and juniper trees in the American Southwest during the past 15 years, setting the stage for further ecological disruption.

Long thought to produce only one generation of tree-killing offspring annually, some populations of mountain pine beetles now produce two generations per year, dramatically increasing the potential for the bugs to kill lodgepole and ponderosa pine trees, University of Colorado Boulder researchers have found.

As if the pine beetle outbreak weren’t bad enough, there’s new evidence to suggest that widespread forest clearing can change precipitation patterns on regional scale, tilting climate toward drought conditions.

It was known early on that the 4 million acres of lodgepole pine infested by the beetle in Colorado and southern Wyoming would drastically change the landscape. The most obvious danger was the dead trees themselves, that unless removed, presented falling hazards for forest users.

Cal Wettstein presides over a sea of dead and dying trees the size of Connecticut. Across his domain, hillsides blanketed with lodgepole pines are in the final throes -- their needles are turning red, or their trunks are tipping precariously to one side. Others are already rotting on the forest floor.