Aerially visible defoliation by the western spruce budworm, Choristoneura occidentalis Freeman, increased from 149,250 acres in 1973 to 649,319 acres in 1974 on five eastern Montana National Forests. An egg mass survey during the fall of 1974 predicted that additional defoliation will occur in 1975 on 47 of 48 plots...
Mountain pine beetle populations reached epidemic levels in 1972 in the Stoney Creek drainage, Ninemile District, Lolo National Forest, Montana. A total of 8,082 trees with an estimated volume loss of 34,356 board feet has occurred from 1972 to 1974. Buildup ratio was 1:1.2 from 1972 to 1973, and 1:1.8...
A supplemental Douglas-fir tussock moth egg mass evaluation was made within three quarter sections north of Poison, Montana, during April 1975. These areas were being considered for a pilot control project of a nucleopolyhedrosis virus spray. Results from the April evaluation showed these areas no longer qualified as sites for...
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...
Evaluation of Douglas-fir tussock moth, Orgyia pseudotsugata, egg masses collected from an outbreak area in the lower Flathead Valley indicated that overall egg viability was relatively high, egg parasitism was low, and virus infestation averaged 7.1 percent northwest of Polson, 17.9 percent south of St. Ignatius, and 57.0 percent west...
Published July 1975. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published November 1975. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published September 1975. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog