The massive area of public forestland -- about million acres -- with trees killed by the mountain pine beetle decreased by 3 million acres between andaccording to a report from the Forest Service. Northern Idaho saw a decrease of nearly 80 percent in beetle-damaged lands from last year. Dwindling reserves of the beetle's choice food, the lodgepole pine, have limited its ability to proliferate, said Robert Mangold, associate deputy chief for research and development for the Forest Service. Since, the numbers have been tumbling.
Mountain Pine Beetle Biology and Management Can the current mountain pine beetle epidemic be stopped? Low-level populations of mountain pine beetles usually attack individual or small groups of trees that have experienced disease, lightning strikes, or other stressors.
Tree mortality might be limited to small areas of lodgepole or ponderosa pine forests that often go unnoticed, or large areas can be impacted.
The combination of an abundance of susceptible forest stands such as those with high tree densities, and large treessuitable environmental conditions such as a droughtand an increasing mountain pine beetle population can set the stage for the development of epidemics.
When populations reach epidemic levels, direct control efforts are generally ineffective. Some efforts were made to control spruce beetle and mountain pine beetle outbreaks in Colorado in the s and s.
But unfortunately, no success was documented. An effort to suppress a mountain pine beetle outbreak in Crater Lake National Park was documented to be ineffective. What factors are contributing to the current extensive mountain pine beetle epidemic?
First, extensive areas of continuous lodgepole and ponderosa pine forests are growing with characteristics that make the stands susceptible to mountain pine beetle—such as the presence of large-diameter trees and dense stands with a high proportion of host trees. Second, drought conditions began in Colorado in the late s, becoming severe by This lack of moisture stresses trees, which then become more susceptible to mountain pine beetle attack.
Third, cold winter temperatures are a primary mortality agent of the mountain pine beetle, and during the last decade or so, Colorado has not experienced sufficiently cold temperatures to trigger significant insect mortality.
How cold do temperatures need to be to trigger insect mortality? There is no simple answer to this question. During this time, they accumulate alcohols that act as an anti-freeze and provide protection from freezing.
The beetles are more susceptible to cold temperatures early in the fall and late spring, when alcohol levels are low, and less susceptible to cold in mid-winter when alcohol levels are highest. Studies show that temperatures from F to F in mid-winter can cause mortality.
However, factors such as the stage of development, duration of exposure to cold temperatures, responses to seasonal changes in temperatures, and geographical location will influence potential mortality. So what temperatures, at what time of the year, or for how long will cause extensive insect mortality is not yet well-understood.
What stand conditions make ponderosa pine forests susceptible to mountain pine beetle? Forest stands with high densities of trees 6 inches in diameter or larger are considered susceptible to mountain pine beetles. Initially, beetles usually do not show a preference for larger-diameter trees, but as the outbreak collapses, or ends, more larger trees are usually killed.
Will mountain pine beetles move from lodgepole pine to ponderosa pine forests? People have raised concerns about the movement of mountain pine beetle from lodgepole pine forests into ponderosa, limber, and Rocky Mountain bristlecone pine stands—all of which are suitable host trees for the mountain pine beetle.
Little research has been conducted on this poorly understood topic. For example, the mountain pine beetle epidemics that occurred in ponderosa pine stands in the Arkansas Valley, in South Park, and around Red Feather Lakes in Colorado in the s and early s, and in the Front Range in the late s and s.
Observations across the West and in southern Wyoming during the current epidemic suggest that the insects are spreading to different hosts.Dawson Creek mountain pine beetle spread analysis: application of the SELES-MPB landscape-scale mountain pine beetle model in the Dawson Timber Supply Area and TFL Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Mountain Pine .
The genome of the mountain pine beetle – the insect that has devastated B.C.’s lodgepole pine forests – has been decoded by research. Mountain pine beetle has been studied extensively, but there is still a lot to learn about its historical distribution, biology and role in the ecosystem.
Parks Canada, in conjunction with its partners, is conducting research to learn more. Many studies are underway in the Mountain National Parks. The mountain pine beetle - identification, biology, causes of outbreaks, and entomological research needs. Proceedings of the joint Canada/USA workshop on mountain pine beetle related problems in western North America.
More research has been conducted on lodgepole pine and mountain pine beetles than any scientific investigations on forest die-off, said Anderegg, who recently co-wrote a paper documenting the. The mountain pine beetle (Dendroctonus ponderosae) is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia.
It has a hard black exoskeleton, and measures approximately 5 mm, about the size of a grain of rice.