An aerial survey during 1974 revealed approximately 5,000 acres of various degrees of Douglas-fir tussock moth, Orgyia pseudotsugata McD., defoliation in the lower Flathead Valley. An egg mass survey was made in September to determine the potential for damage in 1975. Based on new egg mass densities, significant defoliation may...
A western false hemlock looper, Neptyia freeman Munroe, outbreak was detected in the late summer of 1973 at the north end of Flathead Lake. Defoliation, from barely detectable to heavy (most foliage removed from upper half of trees), occurred on Douglas-fir over about 3,000 acres
located between Somers and Kalispell,...
The mountain pine beetle, Dendroetonus ponderosae Hopk., has been at epidemic levels in second-growth ponderosa pine stands in the Ninemile area of the Lolo National Forest and surrounding private lands since 1969. An impact survey, using two levels of photography and a small ground sample, was conducted to estimate a...
The Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., has caused extensive tree mortality for the third consecutive year in the North Fork Clearwater River drainage in northern Idaho. In 1972, the infestation encompassed about 494,080 acres of commercial forest lands in this drainage. It was estimated from a tw-stage aerial photo-ground survey...
The last outbreak of the Douglas-fir tussock moth, Hemerocampa pseudotsugata McD., in the Northern Region subsided in 1965. Tussock moth populations were not detected again until 1970 when ornamental spruce were defoliated in Spokane, Washington, and Poison and Missoula, Montana.
The bark beetle infestation in ponderosa pines defoliated by pine looper, Phaeoura mexicanaria (Grote) on Cook Mountain was resurveyed in 1971. Most of the surviving defoliated trees have "greened up" appreciably. Bark beetle activity was greatly reduced. The red turpentine beetle, Dendroctonus vaZens LeConte, was the only bark beetle observed...
The larch casebearer Coleophora laricella (Hbn.) is now established throughout all western larch stands in Region 1. Population levels have begun to fluctuate in some of the older infested stands; however, it is still on the increase in more recently invaded territory. During the past 2 years work was begun...
An evaluation of the status of bark beetle infestations in ponderosa pine stands on Blue Mountain, Missoula District, Lolo National Forest, was made March 30 and April 4, 1972, at the request of personnel of the Missoula District.
Extensive group killing of ponderosa pine in the vicinity of Blue Mountain...
Treating styroblock containers in hot water (68°C) with a very dilute bleach and detergent solution effectively reduced populations of Fusarium and Cylindrocarpon spp., two potential root pathogens of containerized conifer seedlings. However, the treatment did not significantly reduce levels of Phoma (another potential pathogen) nor saprophytic Penicillium and Alternaria spp....
The series of mountain pine beetle infestations existing on the Plains/Thompson Falls Ranger District, Lob National Forest, since 1971 continued into 1988. While some infestations are waning, others are increasing. The potential for beetle-caused mortality exists in threatened, but as yet uninfested stands. Management alternatives are discussed.
Investigations of containerized conifer seedling root diseases at the Champion Timberlands Nursery revealed that Fusarium oxysporum was most commonly isolated from seed, seedling roots, and styroblock containers. Amount of seed infection varied widely among the seedlots tested, but was usually below 5 percent. Runningwater rinses did not reduce amounts of...
An evaluation of the efficacy of steam treatment on reducing levels of Fusarium, Cylindrocarpon, and
Trichoderma within styroblock containers was conducted at the Plum Creek Nursery in Pablo, Montana. Although levels, of both Fusarium and Cylindrocarpon were significantly reduced by cleaning, relatively high populations of both these fungi persisted after...
Three hundred fifty Leach pine cells used to grow containerized conifer seedlings at the USDA Forest Service Nursery in Coeur d'Alene, Idaho, were sampled for Fusarium and Trichoderma colonization. Cells were either sampled prior to or after cleaning. Cleaning reduced Fusarium colonization from 86 percent of the cells to about...
A total of 45 nondiseased containerized ponderosa pine seedlings from 10 seedlots were sampled at three different times during the growing season for root infection by Fusarium and Trichoderma at the USDA Forest Service Nursery in Coeur d'Alene, Idaho. More than 90 percent of the seedlings had roots infected with...
Investigations of containerized western white pine, western larch, and Douglas-fir seedlings at the Western Forest Systems Nursery in Lewiston, Idaho, revealed that many seedlings were colonized with Fusarium oxysporum although they lacked severe disease symptoms. White pine seedlings were also infected with Pythium spp., probably as a result of sowing...
Investigations were conducted to understand the epidemiology of Fusarium on containerized Douglas-fir seedlings. Types and importance of Fusarium inoculum sources, relationships between seedling infection and symptom production, amounts and types of diseases that occurred throughout typical growth cycles, and the importance of secondary pathogen spread were investigated. Levels of Fusarium...
For the fourth year since their establishment, the six permanent plot locations in Montana were revisited following beetle flight in 1982.Beetle populations remained low in five of the six areas. Only in the Murr Creek plots did newly attacked trees represent an epidemic beetle population. In the Centennial Valley location,...
Thirty permanent mountain pine beetle population trend plots were established in each of six areas in the state in 1979. Infestation levels ranged from 0 to 47.8 new attacks per acre. The potential for increased mortality is considered high for all areas. Each area will be evaluated for 5 years...
Benomyl and chlorothalonil were tested on 2-0 bareroot ponderosa pine seedlings as a means to reduce impact of Diplodia tip blight at the Fantasy Farms Nursery, Peck, Idaho. Infection levels were not adequate to assess effectiveness of the fungicides. However, techniques were developed which can be used to assess efficacy...
The microbial insecticide, Bacillus thuringensis (Bt), was applied from fixed-wing aircraft to approximately 700 acres of western spruce budworm host type at the rate of 12 billion international units (BIU's) per gallon of water per acre. The objective of this control project was foliage protection to insure future cone production...
In conjunction with a proposed suppression project against the Douglas-fir tussock moth in northern Idaho, more than 1,000 larvae were collected from sample plots throughout the 32,000-acre treatment area. We had hoped to determine naturally occurring mortality factors which may have contributed to lower than anticipated population levels. Reared on...
Causes of mortality of containerized western larch seedlings at the Champion Timberlands Nursery, Plains, Montana, were investigated. Seedlings were rated for disease severity based on extent of foliar decline symptoms and fungal isolations made from their roots. Isolations were also made from selected larch seed. Consistent associations between root colonization...