Treesearch

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 nucleopolyhedrosis viruses pathogenic for the western spruce budworm, Choristoneura occidentalis Freeman. This procedure has been used to compare the activity of Baculovirus isolates from several conifer-feeding species of Choristoneura.

This is an annotated assemblage of parasite and hyperparasite records for the Douglas-fir tussock moth. Species in more than 50 genera in the Hymenoptera and Diptera are included. These records are from published literature, unpublished reports, and other miscellaneous sources. These last sources include specimens reared by the author, species identification files (Hopkins US), personal communication with collectors and taxonomists, and determinations by the author of material in collections throughout the West.

During a trapping survey of small mammals (approximately 3,000 individuals), species of fleas (1,632 specimens) were collected in the H.J. Andrews Experimental Forest, Western Cascades, Oregon. Host mammals were represented by 15 species—6 insectivores and 9 rodents captured from June through September. The collections extend our knowledge of the fauna of Oregon.

This report describes a way to collect and classify the total fuel complex within a planning area. The information can be used as input for appraising and rating probable fire behavior and calculating expected costs and losses from various land uses and management alternatives, reported separately as Part 2 and Part 3 of this series. This total package can be used locally for fire management and as input to the land management planning process.

Old-growth coniferous forests differ significantly from young-growth forests in species composition, function (rate and paths of energy flow and nutrient and water cycling), and structure. Most differences can be related to four key structural components of old growth: large live trees, large snags, large logs on land, and large logs in streams. Foresters wishing to maintain old-growth forest ecosystems can key management schemes to these structural components.

Shoot mortality from Sirococcus strobilinus Preuss. and other causes was recorded by crown position from April 1978 through October 1979 in younggrowth western hemlock (Tsuga heterophylla (Raf.) Sarg.) crop trees released in a 1977 thinning at Thomas Bay, Alaska. All study trees contained some infected shoots, but no terminal leaders were killed by shoot blight. On individual trees, the number of shoots killed by S. strobilinus between April 1978 and October 1979 was significantly correlated with the level of shoot blight mortality present in April 1978. Disease occurrence was highest in...

A reinventory in 1973-76 of permanent inventory plots established in 1961-62 on western Oregon's forest industry and other private timberland provides data by ownership of timberland losses to nonforest land uses and changes in private ownership of timberland between inventories.

Releases of Diadegma laricinellum (Hymenoptera: Ichneumonidae), Dicladocerus westwoodii, Dicladocerus japonicus, Chrysocharis laricinellae, Elachertus argissaj, Necremnus metalarus (Hymenoptera: Eulophidae), and Agathis pumila (Hymenoptera: Braconidae) for biological control of the larch casebearer in Oregon, Idaho, and Pennsylvania included some newly imported stocks and additional release locations. More than 14,000 parasites were released at eight sites.

The concept of regional demand is described and applied to the demand for National Forest stumpage. Specifically, demand functions for stumpage (price-quantity relationships) are developed by decade for the major National Forest Regions. The' demand functions are consistent with the 1980 timber program prepared under requirements of the Renewable Resources Planning Act of 1974 (RPA) and provide forest planners with a mechanism to relate National Forest Regional harvest levels to prices.

Seedlings of Pseudotsuga menziesii (Mirb.) Franco, Abies procera Rehd., and Picea sitchensis (Bong.) Carr. were grown for 5 months in growth rooms which simulated hot, warm, or cool growing regimes in greenhouses in western Oregon. Temperature, humidity, light intensity, and photoperiod were changed diurnally and seasonally. In all three species, maximum heights of seedlings were attained in the hot regime, whereas stem diameters were similar under the hot and warm regimes. Dry weight increment was greatest in the warm regime. The cool regime was suboptimal for all aspects of growth....