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....
Mountain pine beetle populations developed to epidemic level in Glacier National Park in 1972. Buildup ratio of old to newly attacked trees was 1:1.8 from 1976 to 1977. More than 12 million trees are infested on 142,871 acres. Buildup ratio is expected to exceed 1:3 from 1977 to 1978. Management...
Epidemic populations of the western spruce budworm persist in the Northern Region. Aerial surveys made in August 1976 showed a decline in the acreage of aerially visible defoliation. In northern Idaho, the defoliated area dropped from 831,487 acres in 1975 to 655,711 acres in 1976, down 21 percent. Surveys in...