Mountain pine beetle developed to epidemic levels in lodgepole pine stands in the Thompson River drainage in 1971. Approximately 506,616 trees are infested on 4,444 hectares. Based on buildup ratios, infestations are expected to intensify; develop in uninfected stands; and kill about 1,763,024 trees in 1977. Salvage logging of infested...
Mountain pine beetle populations began increasing in Glacier National Park in 1970. Numbers of infested trees increased steadily from an average of 12 to 115 per hectare from 1972 to 1976. Total hectares of infestation have increased from 445 in 1972 to 40,419 ha in 1976. Predictive equations estimate a...
Windthrow occurred during late April on the Glacier View, Hungry Horse, Spotted Bear, and Swan Lake Ranger Districts, Flathead National Forest. An evaluation to determine potential for development of spruce beetle and Douglas-fir beetle outbreaks was made during late June and early July. All areas examined were classed as having...
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...
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 reached epidemic levels in the Lap, Cool, Lang, and Caribou Creek drainages in 1974. From 1973 to 1975, approximately 56,282 trees with an estimated volume of 4,365,660 board feet were killed in these areas. An additional 61,721 trees are predicted to be killed in 1976. Currently infested...
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 infestations in the Snell Creek and Warland Peak areas were evaluated in October 1975. Based on current buildup ratios, tree diameter distributions, stand composition and phloem thicknesses, there appears to be limited opportunity for epidemic potential in either area. Management alternatives are discussed. Selective logging is recommended...