This report includes information obtained in both 1983 and 1984. Beginning in 1983, only four of the original six permanent plot locations in the State would be revisited. The two in the southwestern part of the State--Centennial Valley and Madison River--were not visited because of reduced beetle populations and 111.1...
For the fourth year since their establishment, the six permanent plot locations in Montana were revisited following beetle flight in 1982.Beetle populations remained low in five of the six areas. Only in the Murr Creek plots did newly attacked trees represent an epidemic beetle population. In the Centennial Valley location,...
Emerged beetles were first collected July 17 and peak emergence occurred between August 10 and 26, 1975. Density of attacks averaged four per 0.5 ft. 2 (0.05 m2). Parent to brood ratio was 1:4.6. Thirteen associate insects, representing six families of Coleoptera and one of Diptera, were recovered. Associates included...
Mountain pine beetle has occurred at epidemic level in lodgepole pine stands in the west Gallatin River drainage since 1969. Infestation now encompasses about 5,500 acres. Since 1969, approximately 463,212 trees, with an estimated volume of 20,529,244 board feet have been killed. Approximately 69 percent of the stands on the...
Mountain pine beetle reached epidemic levels in the Lazier-Meadow Creek drainages on mixed ownership in 1972. A total of 118,486 trees with an estimated volume of 5,666,124 board feet was killed from 1972 through 1974. Presence of overstocked, mature, nearly pure lodgepole stands, coupled with favorable weather conditions, are believed...
Mountain pine beetle populations reached epidemic levels on approximately 4,600 acres in Glacier National Park in 1972. Infested trees increased from 4.9 in 1972 to 10.9/acre in 1975. Majority of trees killed since 1972 were 12 inches d.b.h. and larger in size. Sufficient large diameter lodgepole pine exists to maintain...
A multistage sampling survey to measure annual and cumulative mortality of lodgepole
pine by mountain pine beetle was conducted
on the Beaverhead and Gallatin National
Forests, 1978-79. The survey area, 270,000
acres, was stratified into three intensity classes
from aerial sketchmapping. This was followed
by large scale (1:6,000) aerial photography,...
Six Montana areas in which permanent mountain pine beetle trend plots were established in 1979 were revisited in 1980. Results of the visit show infestation intensity decreased significantly in Centennial Valley, decreased slightly in the Madison River plot area, and increased almost threefold in the Murr Creek area. Beetle populations...