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...
Aerial and ground surveys to detect and evaluate forest insect and disease conditions in North Dakota were made during June 1977 by personnel from the U.S. Forest Service, Forest Insect and Disease Management staff and the Rocky Mountain Forest and Range Experiment Station. A forest tent caterpillar outbreak in the...
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...
A mountain pine beetle outbreak developed on the north face of Shook Mountain in 1972. Beetle populations increased, and have continued at an epidemic level since 1973. Surveys show 404,798 ponderosa pine containing 12,173,940 bd. ft. volume of merchantable timber; and 20,875 lodgepole pine containing 730,625 bd. ft. volume of...
In spruce budworm damaged areas, height growth loss can be a major factor in stand development. This survey was confined to top-killed trees. Estimates on height growth loss or nontop-killed trees was not attempted. Although spruce did not have as high a percentage of trees top-killed as the true firs,...