About this time of year, mountain pine beetles having spent their childhood and adolescent years burrowing into a nice evergreen take wing, and look for a place to start a family of their own.
The tiny nesters have already laid claim to once deep-green lodgepoles around Granby and along Interstate 70 west of Denver, burrowing under their bark to lay eggs that feed off their pitch. But the beetles don't just like lodgepoles. They're also fond of other species, including the vanilla-scented ponderosas that dominate wild areas along Ute Pass from Colorado Springs to Divide.
The beetles leave a clear trace of where they've been tall stands tinted bright red and orange. Unfortunately for the trees they call home, the nesting beetles are a killer parasite.
This time of year, trees on the verge of releasing new beetles are a straw yellow color. Dennis Will, city Parks & Open Space staff forester, says he recently gazed out over at least 100 infected trees near Green Mountain Falls, a sight that has him worried.
"We're way behind on moisture, and we're desperate for rain," he says. "[The beetles] will have fantastic opportunities to find new host trees."
Will says if drought conditions continue for the next decade, the Ute Pass ponderosas could get eaten alive.
The best intentions
The mountain pine beetles are as much a part of Colorado nature as the elk and the marmot. In a normal ecosystem, they feed on weak, damaged or dying trees. Problem is, in recent years they've fed on the healthy ones too, a result of a dramatically spiking statewide beetle population.
Will says it would take years for Ute Pass to look as bad as Granby. But beetle populations here are increasing. Drought is largely to blame because it weakens trees, making them less able to defend against a beetle attack. But Will says one of the major root causes of beetle infestation has nothing to do with nature. Rather, it's our years of misguided efforts to protect forests.
"We've got stands of trees that should have been burned, that haven't been burned in over 100 years," Will says. "Burning thins the stands out, creates these mosaics, which reduces insect population abilities to build themselves up into epidemic levels."
For us non-foresters, that means when a forest burns in a normal ecosystem, it thins out the trees. The trees that survive don't have as much competition for water and other resources, which makes them healthier.
Fires also help forests create a patchwork of tree species aspens, spruce, grassland, a patch of ponderosas. Since beetles like specific foods, and they won't travel more than about a mile to find a host, the patchwork can keep beetle populations in check.
Turns out, the forests we've fought so hard to protect are now first-class beetle bait. Colorado's lodgepoles, especially, are old and big as beetles prefer. They dominate vast forests with little or no interruption. They are weakened by drought and competition from other large trees. In short, they are sitting ducks.
The ponderosas of Ute Pass, in contrast, tend to be smaller. But they have plenty of other risk factors. They're crowded, thirsty and dominant enough that a beetle wouldn't usually have to fly far to find a new host.
Earlier in the year, the U.S. Forest Service hired contractors to address 150 acres in Woodland Park (see "Beetlemania," cover story, March 13). Infected trees were taken out, and healthy trees were thinned. Eric Zanotto, district fire management officer for the Pike and San Isabel National Forests, says there's been talk of taking on another 150 acres in the Ute Pass area soon.
Spray, they say
The Forest Service, which tends to concentrate on areas that border communities, has two main objectives: remove dead trees that serve as fire hazards and get rid of infected trees before the beetles are full-grown. The latter is usually done in the winter.
"Once the beetles really start flying hard, there's really not much we can do about it," he says.
Beetles aren't just a problem in the forests. They would just as soon munch on your favorite front-yard ponderosa.
Becky Wegner, consulting forester with Mountain High Tree Care in Colorado Springs, says she hasn't seen a big increase in the beetles this year in the city. You're much more likely to have a problem if you live in, say, Chipita Park, Green Mountain Falls or Woodland Park. But that Springs residents still should be concerned, she says.
"I think if you've got a treasured ponderosa pine, yes, you should protectively spray it," she says, adding that spraying is especially pertinent if your neighbor's trees have been infested.
Wegner says consumers should be sure to ask questions before picking a company. A reputable outfit should be licensed by the U.S. Department of Agriculture.
More information on the beetle is available at csfs.colostate.edu.