The mountain pine beetle infestation on Bureau of Land Management lands in Centennial Valley has increased from about 500 acres in 1977 to more than 7,000 in 1979. Average number of trees per acre killed has more than quadrupled, increasing from 9.8 in 1977 to 47.8 in 1979. Predictions for...
Mountain pine beetle infestation was detected in stands on the east side of Glacier National Park and the adjacent Blackfeet Indian Reservation in 1979. Infestation in the Park now encompasses an estimated 215,882 acres. About 200 acres are infested on the reservation. In areas sampled, number of trees killed per...
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,...
1. Defoliation by cankerworms in 1979 was significantly less in 1978 treated shelterbelts than in untreated shelterbelts. 2. Most shelterbelts treated in 1978 retained enough foliage by late June 1979 so that adjacent crops were protected from wind. 3. Aerially applied Bt at a rate of 1/2 lb./acre provided shelterbelt...
Residual Douglas-fir left after harvesting are dwarf mistletoe infected and pose a threat' to regeneration in some units. Removal of residuals, coupled with planned or completed site preparation and thinnings, will effectively reduce dwarf mistletoe incidence and increase future volume yields. The benefit/cost ratio based on timber values alone is...
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...
During December 1978 and January 1979, temperatures reached all-time lows in some parts of Montana. Overwintering mountain pine beetle populations were sampled at 11 sites during February and March 1979. Effects of the extreme cold varied from site to site, with larval mortality ranging from 6 percent to 100 percent....
This report contains an overview of the present mountain pine beetle infestation in lodgepole pine stands on Federal, State, and private lands on the Plains Ranger District. Particular emphasis is placed on the potential for beetle mortality in the Thompson River drainage where recent ground surveys show more than 21...
Mountain pine beetle populations developed to epidemic level in 1970 on the Hebgen Lake Ranger District. Infested acreage increased from 78,000 in 1977 to 79,061 in 1978. More than 4 million trees (238 MMBF) were killed in 1978. Cold temperatures during December 1978 may cause a significant decline in the...
This report contains a brief history of selected mountain pine beetle infestations and the potential for infestations in high hazard stands on the Tally Lake Ranger District. Management alternatives to lessen the severity, or reduce the possibility, of infestations are discussed.
The larch casebearer, Coleophora laricella (Hubner) was first reported attacking western larch, Larix occidentalis, in Idaho in 1957 (Denton, 1958), 71 years after its introduction into Massachusetts from Europe. The apparent successful regulation of this insect in the eastern U.S. by introduced parasites prompted biological control attempts in the West....
A needle miner, Coleotechnites sp., defoliated approximately 3,100 acres of ponderosa pine, Pinus ponderosa Laws. on the Flathead Indian Reservation, Montana, during 1978. Three other small areas in the Missoula Valley were infested also. Overwintering populations of larvae are low; thus, light defoliation is expected in 1979 in presently infested...
The forest tent caterpillar, Malacosoma disstria Hbn., began defoliating trembling aspen stands, Populus tremuloides Michx., in 1976 in the Turtle Mountains of North Dakota. Heavy defoliation was scattered through about 150,000 acres in 1978. Pupal mortality from parasites and disease was almost 100 percent in cocoons on understory shrubs and...
Eradication of Ribes spp. to control white pine blister rust in Yellowstone National Park was started in 1947. In 1968 this study was initiated to evaluate the previous control effort. Ribes eradication was suspended in 1968 in 18 white pine stands and Ribes and rust were allowed to increase within...
Residual Douglas-fir in older clearcuts are dwarf mistletoe-infected and pose a threat to regeneration present. Removal of these residuals coupled with planned or completed precommercial thinnings will effectively reduce dwarf mistletoe to an insignificant level and increase future volume yields. The benefit/cost ratio based on timber values alone is negative,...
Residual lodgepole pine in older clearcuts are dwarf mistletoe-infected and pose a threat to regeneration present. Removal of these residuals coupled with planned or completed precommercial thinnings will effectively reduce dwarf mistletoe to an insignificant level and increase future volume yields. The benefit/ cost ratios based on timber values alone...
Residual lodgepole pine in older clearcuts are dwarf mistletoe-infected and pose a threat to regeneration present. Removal of these residuals coupled with planned or completed precommercial thinnings will effectively reduce dwarf mistletoe to an insignificant level and increase future volume yields. The benefit/cost ratio based on timber values alone is...