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A technique is described for sampling spruce budworm larvae after bud flush by nondestructively beating branches in the lower crown. Sample data were collected from 32 plots representing a wide range of budworm densities. Statistical analyses indicated that larvae were less aggregated in the lower…
Author(s): R.R. Mason, B.E. Wickman, H.G. Paul
Keywords: Sampling insects, insect defoliators, western spruce budworm, Choristoneura occidentalis
Source: Res. Note PNW-RN-486. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 8 p
Year: 1989
The relative virulence of entomopathogenic viruses and the potency of virus preparations for control of destructive insects can be estimated reliably only by means of biological assay in the target species. A simple, yet sensitive peroral bioassay procedure is described for preparations of…
Author(s): Mauro E. Martignoni, Paul J. Iwai
Keywords: Bioassay, Baculovirus, nucleopolyhedrosis virus, virus (insect), diseases (insect), quality control (virus preparations), biological control (forest pests), western spruce budworm, Choristoneura occidentalis
Source: Res. Pap. PNW-RP-285. Portland, OR: U.S. Department of Agriculture, Forest Service. 20 p.
Year: 1981
Procedures for monitoring larval populations of the Douglas-fir tussock moth and the western spruce budworm are recommended based on many years experience in sampling these species in eastern Oregon and Washington. It is shown that statistically reliable estimates of larval density can be made for…
Author(s): A.R. Mason, H.G. Paul
Keywords: Ecological monitoring, population monitoring, sampling insects, Douglas-fir tussock moth, Orgyia pseudotsugata, western spruce budworm, Choristoneura occidentafis
Source: Gen. Tech. Rep. PNW-GTR-333. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 p
Year: 1994
Pupal density of western spruce budworm, Choristoneura occidentalis Freeman, can be accurately estimated from 45-cm branch tips. Density on tips was representative of densities on entire branches. Mean pupal densities on branch tips are statistically different from lower, mid, and upper…
Author(s): Nilima Srivastava, Roy C. Beckwith, Robert W. Campbell, Torolf R. Torgersen
Keywords: Population sampling, insect surveys, sampling methods, insect populations, western spruce budworm, Choristoneura occidentalis
Source: Res. Note PNW-RN-372. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station 6 p
Year: 1981
Mortality between 1991 and 1995 destroyed a levels-of-growing-stock study installed in four widely separated blocks in the Deschutes and Fremont National Forests in Oregon. Mortality at one block was attributed to root rot (Armillaria ostoyea (Romagnesi) Herink) and western spruce budworm…
Author(s): P.H. Cochran
Keywords: White fir, stand density, mortality, periodic annual increments, fir engraver, Modoc budworm, root rot, western spruce budworm
Source: Res. Note PNW-RN-525. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 19 p
Year: 1998
This paper documents methods for assessing the potential effects of variable-intensity management in late-successional reserves (LSRs) and provides an example (the Gotchen LSR) from the Cascade Range in eastern Washington. The Gotchen LSR study investigates changes in forest vegetation associated…
Author(s): Susan Stevens Hummel, R. James Barbour, Paul F. Hessburg, John F. Lehmkuhl
Keywords: Forest reserves, northern spotted owl, restoration silviculture, habitat management, western spruce budworm, fire hazard
Source: Res. Note PNW-RN-531. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 25 p
Year: 2001
The purpose of this study was to determine the effect of time since death over a 4-year period on the amount of usable product volume and value, and to determine the species of fungi associated with wood deterioration in the stems of Douglas-fir and grand fir trees killed by bark beetles in…
Author(s): Dean L. Parry, Gregory M. Filip, Susan A. Willits, Catherine G. Parks
Keywords: Douglas-fir, Pseudotsuga menziesii, grand fir, Abies grandis, lumber recovery, utilization, dead timber, western spruce budworm, Choristoneura occidentalis, Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, fir engraver, Cryptoporus volvatus, Trichaptum (Polyporus) abieinum, Fomitopsis pinicola
Source: Gen. Tech. Rep. PNW-GTR-376. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 24 p
Year: 1996
The Budworm Model predicts the amounts of foliage destroyed annually by the western spruce budworm, Choristoneura occidentalis Freeman, in a forest stand. The model may be used independently, or it may be linked to the Stand Prognosis Model to simulate the dynamics of forest stands. Many…
Author(s): K.A. Sheehan, W.P. Kemp, J.J. Colbert, N.L. Crookston
Keywords: Model, population dynamics, insect populations, defoliation, stand growth and yield, western spruce budworm, Choristoneura occidentalis, Tortricidae
Source: Gen. Tech. Rep. PNW-GTR-241. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 70 p
Year: 1989
This publication describes how to use version 2 of the Regeneration Establishment Model, a computer-based simulator that is part of the Prognosis Model for Stand Development. Conifer regeneration is predicted following harvest and site preparation for forests in western Montana, central Idaho, and…
Author(s): Dennis E. Ferguson, Nicholas L. Crookston
Keywords: succession, stand simulation, Northern Rocky Mountains, forest planning, western spruce budworm, Choristoneura occidentalis
Source: Gen. Tech. Rep. INT-279. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 34 p.
Year: 1991
A sample of 133 Douglas-firs (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and 69 true firs (Abies spp.) with dead tops caused by defoliation by the western spruce budworm (Choristoneura occidentalis Freeman) were felled, dissected, and examined for height…
Author(s): Paul E. Aho
Keywords: Insect damage (-forest, increment (height), crown damage, decay (wood), heartwood rot, western spruce budworm, Douglas-fir, Pseudotsuga menziesii, true fir, Abies spp, Washington (eastern), eastern Washington
Source: Res. Pap. PNW-RP-318. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 8 p
Year: 1984
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