Insects and diseases have the potential of seriously affecting timber associated resources on eastside forests within the foreseeable future. Within the past decade, lodgepole pine mortality attributed to the mountain pine beetle has totaled tens of millions of trees on the Gallatin and Beaverhead National Forests (NF) alone. In that...
Insect damage was extensive to Douglas-fir, ponderosa pine, western white pine, and western larch cones at most seed production areas surveyed in 1979. From 70 to 100 percent of the cones from several collecting periods were injured. Moderate damage (40-70 percent of cones injured) occurred to Douglas-fir, ponderosa pine, western...
An evaluation was made in 21 seed production areas and 1 seed orchard in Region 1 to identify the primary insect pests and to assess amount of injury caused. Cones from Douglas-fir, grand fir, western larch, lodgepole pine, ponderosa pine, and western white pine were collected periodically and examined. The...
We analyzed the effects of pathogens and insects on forest succession in the absence of
fire or management, addressing a number of related questions:
1. What is the rate of change in such forests?
2. How significant are the roles of pathogens and insects in the forest change?
3. How...
Ground surveys on the Hungry Horse District indicate a potential for mountain pine beetle infestation in lodgepole pine. Based on elevation-latitude, mean d.b.h. and phloem thickness, and age, stands were given a susceptibility classification of high risk. An infestation in Glacier National Park may provide the beetle source. Management alternatives...
The mountain pine beetle reached epidemic levels in second-growth 80-yearold ponderosa pine stands on the Ninemile Ranger District in 1969. The
outbreak increased through 1971 and spread over 30,000 acres. Heavy
infestation occurred on about 2,600 acres within this area. A two-stage
survey was used during 1972 and 1973 to...
We conducted a combination road/plot impact survey for dwarf mistletoe in lodgepole pine on six East Side National Forests in 1978. The road survey showed infestation percentages ranging from 28.2 on the Custer to 52.4 on the Beaverhead. The plot survey showed annual cubic foot volume losses ranging from 106M...
Mountain pine beetle populations increased in 1979 in the Thompson River drainage to levels predicted following the 1978 attack period. New attacks in 1979 averaged 27 per acre. Current estimates indicate another 25 percent of the remaining lodgepole pine could be killed in 1980.
This evaluation showed that Bt provided measurable foliage protection 1 year after treatment, but no differences were evident after 2 years. We recommend future Bt tests include postspray population measurements in the pupal and/or adult, and/or egg stage, and that foliage protection be measured the following year. The effects of...