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...
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...
Mountain pine beetle populations developed to epidemic level on the Bozeman-Gallatin Ranger District in 1969. Approximately 146,000 acres are currently infested. Since 1969, over 350 MMBF have been killed. It is predicted that over 4 million trees could be killed in 1978. Infestation is predicted to intensify in high-hazard stands....
Mountain pine beetle populations reached epidemic level on the Hebgen Lake Ranger District in 1970. Infested area increased from 6,680 acres in 1970 to 78,000 acres in 1977. Buildup ratio of trees killed in 1976 to trees killed in 1977 is 1:8. Approximately 1,700,000 trees, containing 175 MMBF of merchantable...
Large areas of dwarf mistletoe-free, all-aged lodgepole pine have been identified in the West Yellowstone Basin. The option of uneven-aged management in these areas remains available to the District.
Mountain pine beetle developed to epidemic level in lodgepole pine stands in 1969 on the Gallatin District and in 1970 on the Hebgen Lake District. Epidemic infestation occurs on 53,437 hectares. Infestations will intensify in most areas currently infested and develop in uninfested stands, and in excess of 2 million...
Mountain pine beetle infestations have continued at epidemic level in
lodgepole pine stands since 1969 in the West Gallatin River drainage.
This infestation has increased at about a 1.9:1 buildup ratio annually.
Since the outbreak began in 1969, surveys indicate that approximately 22,354 merchantable size trees have been killed with...
Dipel (R) was applied by helicopter to three blocks of Douglas fir and Engelmann spruce infested with Choristoneura occidentalis Free., in southwestern Montana. Dosage was 1 pound (7.2 Bill) in 2 gallons of water/acre (453 g in 7.5 t/0.4 ha). A commercial surfactant, Bio-film (R) was added at the rate...