Cone and seed insects and their impact on whitebark pine

Whitebark pine, Pinus albicaulis Engelm. is an important but declining high-elevation tree species in western forests. Regeneration of this species has been difficult and the impact of cone and seed insects unknown. Seven sites selected from the geographical range of whitebark pine in Idaho, Montana, Washington, Oregon, and California were examined for cone and seed insects and their impact. Ten different insect species were found affecting various reproductive structures of whitebark pine. Insects having the greatest impact across most sites were fir coneworm (Dioryctria abietivorella (Grote)) and western conifer seed bug (Leptoglossus occidentalis Heidemann). Coneworms infested up to 68% of cones collected, destroying up to 13% of the seed extracted. Seed bugs damaged up to 27% of the seeds. Pheromone traps for the ponderosa pine cone beetle (Conophthorus ponderosae Hopkins) and coneworms were tested. Ponderosa pine cone beetles were trapped at three of seven sites. Coneworms were trapped at two sites where pheromone traps were deployed. Further studies incorporating different cone crop levels of whitebark pine and other associated tree species are needed to fully determine the effect of cone and seed insects on whitebark pine seed and reproduction

Douglas-fir beetle population assessment : Idaho Panhandle National Forests

The unusually large amount of ice, snow, and wind-damaged trees that occurred during the winter of 1996-97 provided prime habitat for populations of the Douglas-fir beetle (DFB) (Dendroctonus pseudotsugae) to build to epidemic numbers. Beetles emerged during the spring and summer of 1998, attacking hundreds of thousands of standing Douglas-fir trees. Beetle attacks continued in green trees in 1999. This report documents DFB population assessments in 1999, including ground surveys of current beetle populations and aerial survey, which reports 1998 killed trees

An assessment of chloride-associated, and other roadside tree damage, on the Selway Road, Nez Perce National Forest

Tree damage following dust abatement/road stabilization treatment was evaluated on 12.5 miles of the Selway River Road, Nez Perce National Forest. Calcium chloride was applied in June of 2000, mostly at a rate of 51b/yd2 (18,600 lb./acre) or 6.9 lb/yd 2 (25,700 lb/acre). 1,189 trees up to 30 feet from the road were examined in June 2001 and again in December 2001. Western redcedar and Douglas-fir were most damaged by the chloride. Ponderosa pine was the most tolerant of the tree species. Severity of damage was associated with tree species, proximity of trees to road, and CaCl2 application rates. Cedar foliage samples collected in November 2001 from symptomatic trees near treated road averaged nearly seven times more chloride ion concentration than the controls. Treated Douglas-fir averaged 50 times more and ponderosa pine average 30 times more than their respective controls. As of December 2001, 12% of cedars were dead and another 18% appear to be dying. Douglas-fir fared worse with 29% dead and 12% dying. Grand fir and ponderosa pine had only 6% and 4%, respectively, dead or dying

Effects of topical application of the biological control agent Biotrek on production of bareroot Douglas-fir and western white pine seedlings, USDA Forest Service Nursery, Coeur d'Alene, Idaho

A preliminary evaluation of the biological control formulation of Trichoderma harzianum marketed as BioTrek® was conducted on bareroot Douglasfir and western white pine seedlings at the USDA Forest Service Nursery, Coeur d'Alene, Idaho. The biocontrol material was applied topically on seed shortly after sowing and comparisons made between treated and untreated 1-0 and 2-0 seedlings. First-year Douglas-fir height and second-year white pine height and diameter were not affected by the treatment. BioTrek® significantly reduced white pine seedling root infection by Cylindrocarpon spp., but not by either Fusarium or Trichoderma spp. The major Fusarium species isolated from roots of nondiseased seedlings was F. oxysporum. Further tests of BioTrek® are underway at the nursery

Douglas-fir tussock moth in northern Idaho and western Montana : current activity and historical patterns

The objective of this report is to describe the current increase in Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) activity in northern Idaho and Montana. The report also relates current conditions to historical and future trends and larger scale increasing tussock moth activity in surrounding western states

Pathogenic characteristics of Fusarium acuminatum isolated from inland Pacific Northwest nurseries

Thirty-three isolates of Fusarium acuminatum obtained from inland Pacific Northwest forest nurseries were tested for their pathogenicity on young Douglas-fir germinants under controlled laboratory conditions. Tested isolates were from forest nursery soil, roots of healthy-appearing and diseased conifer seedlings, Styrofoam and hard plastic containers, conifer seeds, 411 and adult fungus gnats. The vast majority of isolates were non-pathogenic under test conditions. A few isolates from roots of healthy-appearing or diseased seedlings displayed low or moderate virulence. Although isolates of F. acuminatum are routinely encountered in forest nurseries, they are probably not important pathogens under most conditions and should usually not be considered a threat to seedling production

Investigations of tree health at the Potlatch Corporation Cherrylane Seed Orchard, Idaho

Investigations were conducted from 1998- 2000 at the Potlatch Corporation's Cherrylane Seed Orchard near Lewiston, Idaho to evaluate presence and extent of potentially pathogenic fungi on roots of diseased stock and within the soil in current and proposed plantation sites. The most common group of pathogens encountered was Fusarium spp.; F. oxysporum was by far the most common colonizer of tree roots and soil. Phytophthora spp. (P. cacta rum and P. pseudotsugae) and Pythium spp. (P. irregulare and P. ultimum) were also common root and soil colonizers. Cylindrocarpon spp. (C. destructans and C. tenue) were isolated at lower frequencies. Soil solarization with a thin plastic tarp during the summer effectively reduced populations of potential soil-borne pathogens. Managers should continue to monitor pathogen populations on stock and within soil of proposed plantation sites in order to reduce future disease impacts

Effects of spring applications of dazomet on root diseases and performance of Douglas-fir and western white pine transplants, USDA Forest Service Nursery, Coeur d'Alene, Idaho

Tests were conducted at the USDA Forest Service Nursery, Coeur d'Alene, Idaho to evaluate effectiveness of spring fumigation with dazomet to improve survival and performance of Douglas-fir and western white pine transplants. Spring fumigation greatly reduced populations of potentially pathogenic Fusarium and Pythium spp. Disease levels of container (plug+1) and bare root (2+1) Douglas-fir transplants were very low, regardless of soil fumigation. Fumigation reduced disease on bare root (2+1) white pine transplants, but did not improve survival of container (plug+1) white pine transplants. Seedling height growth during the first year after transplanting was significantly improved by soil fumigation. Fusarium oxysporum was commonly isolated from soil and roots of diseased bare root transplants. Fusarium proliferatum was commonly isolated from the roots of container transplants. Soil fumigation may not necessarily improve survival and performance of all types of conifer transplants in nurseries