Windthrow occurred during late April on the Glacier View, Hungry Horse, Spotted Bear, and Swan Lake Ranger Districts, Flathead National Forest. An evaluation to determine potential for development of spruce beetle and Douglas-fir beetle outbreaks was made during late June and early July. All areas examined were classed as having...
An evaluation of the status of bark beetle infestations in ponderosa pine stands on Blue Mountain, Missoula District, Lolo National Forest, was made March 30 and April 4, 1972, at the request of personnel of the Missoula District.
Extensive group killing of ponderosa pine in the vicinity of Blue Mountain...
Douglas-fir beetle has increased to epidemic levels in mature-overmature Douglas-fir that has been top killed by western spruce budworm. About 42 trees per acre have been killed in an area at Lyon's Face and 36 trees per acre in other areas along the Madison River during the past 3 years....
Mountain pine beetle, Dendroctonus ponderosas Hopk., reached near epidemic levels in lodgepole pine stands in the Sulphur Creek-Black Butte area. Lodgepole pine are probably more susceptible due to the overstocked conditions of stands, and high incidence of girdling of the base of trees by porcupines. The infestation in this area...