Feb 092012
Authors: Emily Smith

Fort Collins’ forests are infested.

Mountain pine beetles coordinate mass attacks, bore into bark and tunnel inside trees to hatch their larvae, according to CSU’s online fact sheet. And the beetles’ lifestyle comes at the expense of pine trees in Fort Collins and across Colorado.

“We’re in an epidemic time for mountain pine beetle,” said Boyd Lebeda, a forester for the Colorado State Forest Service.

“This last year was especially a strong spread of the pine beetle,” said Jim Linden, a professor of Microbiology, Pathology and Immunology.

“We have a forest that is susceptible to mountain pine beetle,” Lebeda said, “because a large part of it is similar-aged, fairly old and fairly dense.”

These factors, coupled with the drought period in Colorado around 1999 to 2000, made a lot of suitable trees for the mountain pine beetle to get in, according to Lebeda.

Lebeda said the mountain pine beetle epidemic developed over a period of 12 to 15 years, mostly up in the mountains in lodgepole pines.

“In 2008, there were really, really large populations in the mountains,” Lebeda said. “The beetles usually don’t fly very far from tree to tree –– usually a mile or less –– but the populations got so big they had to fly higher in the atmosphere.”

Because of this, the beetles got blown many miles by the wind and dispersed into other areas.

“That is probably how they ended up in Fort Collins,” Lebeda said.

An example of this process in Fort Collins is the Soapstone Prairie Natural Area, where a stand of isolated ponderosa pines was infected with the beetle even though it was not near any other pine forests.

Linden said that the pine beetle could also have spread into the urban areas of Fort Collins when people bring infected firewood from the mountains.

“The pine beetle is still under the bark,” Linden said. “So it just serves as a reservoir.”

However, while the mountains around Fort Collins and across the state have lost millions of pines, the city of Fort Collins has seen a somewhat lesser impact.

“One of the things we saw was a much lower percentage of mortality with trees in the city,” Lebeda said. “The pines we have in the city are generally going to be on some kind of irrigated lawn or park –– somewhere they get some care.”

“The mountain pine beetle has certainly affected the aesthetics of Fort Collins,” said Sky Stephens, forest entomologist for the Colorado State Forest Service, “but most of the impact to date has probably been relatively small and on a personal scale.”

Homeowners and businesses have lost trees on their properties, and some “character” trees have been removed, such as some near the Lincoln Center, according to Stephens.

“Compared to many communities harder hit than Fort Collins,” Stephens said, “the impacts of MPB seem small in our area.”

While the impacts of the mountain pine beetle are not major yet in Fort Collins, there is still no feasible way to control the population of beetles.

“Treatment means removing the tree,” Lebeda said, “and treating the wood somehow so you kill the larvae in there.”

With such a large and growing population, this controlled strategy of mechanical treatment is difficult, Lebeda said.

Forestry services has tried spraying insecticides and setting pheromone traps for the beetles to kill or divert them, but it is not practical to do that for every tree in Colorado, or even the Fort Collins area, according to Lebeda.

Linden has invented a new product called Organic Disease Control (ODC).

“It changes the physiology of the tree so it produces more resin,” Linden said. “When the beetle bores through the bark, resin flows out through the wound.”

Linden explained that if this resin flow is sufficient, then the beetle cannot enter the tree and lay her eggs under the bark.

For more information about the mountain pine beetle, students are encouraged to visit csfs.colostate.edu or contact the City of Fort Collins forestry department at (970)-221-6660.

Collegian writer Emily Smith can be reached at news@collegian.com.

Fast Facts
-Mountain pine beetle (MPB) activity in Colorado began in 1996
-The MPB is native to the forests of western North America
-It develops in lodgepole, ponderosa, Scotch and limber pines
-Outbreaks of MPB have resulted in the loss of millions of trees

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