An attempt was made to predict western spruce budworm defoliation using
egg counts from plots in the Douglas-fir type east of the Continental
Divide in Montana, the Douglas-fir type west of the Continental Divide
in Montana, and the mixed grand fir Douglas-fir type of northern Idaho.
The parameters used in...
Western spruce budworm defoliated area in the Northern Region has differed significantly across three discrete geographic zones during the past decade. Aerially visible defoliation in northern Idaho increased from 1.7 million acres in 1969 to a high of 2.2 million acres in 1974, and declined to none in 1979. Defoliated...
Stepwise multiple regression techniques were used to statistically analyze the relationships between damage caused by the pine needle sheath miner Zellaria haimbachi (Busck); a needle miner, Oenerostoma etrobivorum (Zeller); sugar pine tortrix, Choriatoneura Zambertiana (Busck); and ambient and foliar concentrations of fluoride in lodgepole pine (Pinue contorta v. Zatifolia Engelm.)...
In spruce budworm damaged areas, height growth loss can be a major factor in stand development. This survey was confined to top-killed trees. Estimates on height growth loss or nontop-killed trees was not attempted. Although spruce did not have as high a percentage of trees top-killed as the true firs,...
Aerial and ground surveys to detect and evaluate forest insect and disease conditions in North Dakota were made during June 1977 by personnel from the U.S. Forest Service, Forest Insect and Disease Management staff and the Rocky Mountain Forest and Range Experiment Station. A forest tent caterpillar outbreak in the...
A looper, probably the Bruce spanworm, Operophtera bruceata (Hulst), defoliated more than 15,650 acres of quaking aspen in the Turtle Mountains of North Dakota in the spring of 1973.
Shade tree insect and disease activity within the city limits of Bozeman, Montana, were evaluated. Other than a few minor insects, the park, cemetery, and street trees are in remarkably good condition. Both the Park Department and private homeowners appreciate the value of trees in the urban environment. Recommendations on...
A supplemental Douglas-fir tussock moth egg mass evaluation was made within three quarter sections north of Poison, Montana, during April 1975. These areas were being considered for a pilot control project of a nucleopolyhedrosis virus spray. Results from the April evaluation showed these areas no longer qualified as sites for...
We analyzed the effects of pathogens and insects on forest succession in the absence of
fire or management, addressing a number of related questions:
1. What is the rate of change in such forests?
2. How significant are the roles of pathogens and insects in the forest change?
3. How...
Over 10,000 acres of aerially visible western hemlock looper defoliation on grand fir was detected on State and Federal forests of central Idaho in 1972. This is the first report of this insect building up
in Region 1 since a widespread outbreak in 1937-39.
The western hemlock looper has the...
The variable oak leaf caterpillar, Heterocampa manteo (Dbldy.), has defoliated hardwoods in two North Dakota locations for 3 years (Fig. 1). This is the second consecutive year its damage has been monitored. Monitoring has been done cooperatively with William Brandvik, Associate
State Entomologist, North Dakota Department of Agriculture.
Mountain pine beetle populations began building in the Kootenai National Forest in 1972. Infestations now encompass an estimated 48,599 acres of lodgepole pine type and 615 acres of ponderosa pine type. Approximately 25 percent of the high-risk stands, 17 percent of the moderate-risk, and less than 1 percent of the...
Mountain pine beetle activity has increased from about 350 infested trees in 1972 to over 1,200 infested trees in 1974 on the Bitterroot National Forest. The majority of infestation occurs in second-growth, overstocked, ponderosa pine stands in the West Fork Bitterroot drainage. An increase in number of trees killed is...
The mountain pine beetle, Dendroctonus ponderosae Hopk., infestation in Yellowstone National Park advanced north and eastward in 1974. New infestation centers were located along the east shore of Yellowstone Lake and south of the Promontory to the Park's southern boundary. Ground surveys indicated an average of 2.9 infested trees per...
The mountain pine beetle infestation has been epidemic in lodgepole pine in Yellowstone National Park since 1966. Infestation boundaries have advanced steadily northward and eastward. The infestation now encompasses nearly one-half of the total Park area. Surveys indicate a decline in tree mortality the last 2 years. In 1970, an...
Mountain pine beetle populations increased to epidemic levels on the Kootenai National Forest in 1972. Nearly 397,000 trees containing almost 32 million board feet have been killed. More than 84,000 trees will probably be killed in 1978. Infestation has the potential to intensify in high hazard stands, and some increase...
Mountain pine beetle populations reached epidemic levels on approximately 4,600 acres in Glacier National Park in 1972. Infested trees increased from 4.9 in 1972 to 10.9/acre in 1975. Majority of trees killed since 1972 were 12 inches d.b.h. and larger in size. Sufficient large diameter lodgepole pine exists to maintain...
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...
Mountain pine beetle infestations have continued at epidemic level in
lodgepole pine stands since 1969 in the West Gallatin River drainage.
This infestation has increased at about a 1.9:1 buildup ratio annually.
Since the outbreak began in 1969, surveys indicate that approximately 22,354 merchantable size trees have been killed with...
A mountain pine beetle infestation has been active in the St. Regis area since 1964. Heaviest tree mortality occurred during the period 1969-70. The infestation has continued to decline since 1970. Over 2 million board feet of lodgepole and ponderosa pine were killed during the outbreak. Overstocking resulted in slow...
Mountain pine beetle infestations in second-growth ponderosa pine developed in 1973 in the Little Rocky Mountains. In 1976, increasing numbers of attacked trees were observed. Current infestation intensity averages 7.1 trees per acre. Losses are expected to continue as long as stands remain overstocked and stagnated. Reduction of basal area...
Mountain pine beetle infestations in second-growth ponderosa pine have been chronic in the Little Belt and Big Snowy Mountains since 1947. In 1976, increasing numbers of attacked trees were observed. Current infestation intensity averages 82 trees per hectare. Losses are expected to continue as long as stands remain stagnates. Commercial...
Mountain pine beetle populations began increasing in Glacier National Park in 1970. Numbers of infested trees increased steadily from an average of 12 to 115 per hectare from 1972 to 1976. Total hectares of infestation have increased from 445 in 1972 to 40,419 ha in 1976. Predictive equations estimate a...
Mountain pine beetle developed to epidemic level in lodgepole pine stands in 1969 on the Gallatin District and in 1970 on the Hebgen Lake District. Epidemic infestation occurs on 53,437 hectares. Infestations will intensify in most areas currently infested and develop in uninfested stands, and in excess of 2 million...
Mountain pine beetle populations developed to epidemic level on the Bozeman-Gallatin Ranger District in 1969. Approximately 146,000 acres are currently infested. Since 1969, over 350 MMBF have been killed. It is predicted that over 4 million trees could be killed in 1978. Infestation is predicted to intensify in high-hazard stands....
Windthrow occurred during late April on the Glacier View, Hungry Horse, Spotted Bear, and Swan Lake Ranger Districts, Flathead National Forest. An evaluation to determine potential for development of spruce beetle and Douglas-fir beetle outbreaks was made during late June and early July. All areas examined were classed as having...
Mountain pine beetle infestations have increased in second-growth ponderosa pine stands in the Garnet Mountains since 1971. The extremely dry 1973 season resulted in an increase of Ips engraver beetle activity that was responsible for over half of the tree mortality in 1973. Commercial thinning is recommended to alleviate the...
The current western spruce budworm, Choristoneura occidentalis Freeman, outbreak on the Clearwater National Forest was first detected in 1966. Since then, the infestation has increased to epidemic proportions with over 500,000 acres of State, Federal, and private forest land visibly defoliated. In addition, incipient budworm populations are present throughout much...
Diseased conifer nursery stock, including Douglas-fir, western larch, and Engelmann spruce, was selected from the U.S. Forest Service nursery at Coeur d'Alene, Idaho, to determine (1) the most probable cause of disease, (2) the fate of outplanted diseased stock, and (3) the height growth of outplanted diseased seedlings. Fusarium spp....
An impact survey to determine extent and distribution of root disease centers was completed for the Nezperce National Forest, Idaho, in 1980. Lowlevel
color infrared photography was used to delineate root disease centers
within National Forest inventory subcompartments. Suspected root disease
centers were ground checked to determine associated fungi and...
The western hemlock looper, Lambdina fiscellaria Zugubrosa Hulst, caused, aerially visible defoliation on approximately 10,000 acres of State, private, and Federal forests of northern Idaho in 1972. This is the first report of noticeable defoliation by this insect in Region 1 since the late 1930's (Dewey et al. 1972).
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....
The purpose of insect and disease damage surveys is to estimate losses caused by various pests, so that the land manager can prescribe appropriate management action. Systematic ground data collection systems provide to the land manager loss data that can be used for cost benefit analysis, management plans, environmental impact...
Based on per acre costs, plantation establishment is one of the most expensive silvicultural practices (Pfister 1976), but only token studies have been done on frequency and causes of seedling injury and mortality in Region 1 plantations (Wenner 1976). Therefore, we conducted a survey in 1978 on four National Forests...
The pine butterfly, Neophasia menapia Feld., has been at epidemic levels in the Bitterroot and Missoula valleys for the past 2 years (Ciesla et al. 1971) (Bousfield and Meyer 1972). Several reports of conspicuous pine butterfly flights on the Flathead Indian Reservation prompted an evaluation of the potential for pine...
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...
Ground surveys on the Hungry Horse District indicate a potential for mountain pine beetle infestation in lodgepole pine. Based on elevation-latitude, mean d.b.h. and phloem thickness, and age, stands were given a susceptibility classification of high risk. An infestation in Glacier National Park may provide the beetle source. Management alternatives...
Epidemic levels of the pine butterfly, Neophasia menapia (Felder and
Felder) have been evident in ponderosa pine stands in the Bitter Root
Valley since 1969. Evaluations of this infestation were initiated in
1970 to assess overwintering egg populations at 20 locations within
the infestation (Ciesla et al. 1971). Defoliation was...
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...
Aerial surveys of six Montana National Forests in 1975 found a 22.1% increase in the area of visible defoliation caused by the western spruce budworm. It is estimated that 2,278,804 acres of Douglas-fir forests are now suffering at least 25% defoliation. This is an increase of 503,706 acres over the...
Aerially visible defoliation by the western spruce budworm, Choristoneura occidentalis Freeman, increased from 149,250 acres in 1973 to 649,319 acres in 1974 on five eastern Montana National Forests. An egg mass survey during the fall of 1974 predicted that additional defoliation will occur in 1975 on 47 of 48 plots...
In 1973, two centers of defoliation by Douglas-fir tussock moth totaling 350 acres were detected near Missoula, Montana. Egg mass surveys showed two sections south of Frenchtown and one section northwest of Lolo 41, contain sufficient egg mass population to cause heavy defoliation in 1974.
A needle miner, Coleotechnites sp., defoliated approximately 3,100 acres of ponderosa pine, Pinus ponderosa Laws. on the Flathead Indian Reservation, Montana, during 1978. Three other small areas in the Missoula Valley were infested also. Overwintering populations of larvae are low; thus, light defoliation is expected in 1979 in presently infested...
The forest tent caterpillar, Malacosoma disstria Hbn., began defoliating trembling aspen stands, Populus tremuloides Michx., in 1976 in the Turtle Mountains of North Dakota. Heavy defoliation was scattered through about 150,000 acres in 1978. Pupal mortality from parasites and disease was almost 100 percent in cocoons on understory shrubs and...
Six Montana areas in which permanent mountain pine beetle trend plots were established in 1979 were revisited in 1980. Results of the visit show infestation intensity decreased significantly in Centennial Valley, decreased slightly in the Madison River plot area, and increased almost threefold in the Murr Creek area. Beetle populations...
Eighteen isolates of Fusarium comprising four species (F. oxysporum, E. avenaceum, E. acuminatum, and F. sambucinum) isolated from diseased conifer seedlings from nurseries were tested for pathogenicity on Douglas-fir germlings. Three of the most pathogenic F. oxysporum isolates on Douglas-fir germlings were also tested on ponderosa pine germlings and older...
During December 1978 and January 1979, temperatures reached all-time lows in some parts of Montana. Overwintering mountain pine beetle populations were sampled at 11 sites during February and March 1979. Effects of the extreme cold varied from site to site, with larval mortality ranging from 6 percent to 100 percent....
The western spruce budworm, Choristoneura occidentalis (Free.), has caused a measurable impact on a portion of the Flathead Indian Reservation during a 5-year infestation period. This survey showed that most of the grand fir and alpine fir, and 13.8 percent of the Douglas fir has been top killed in the...
Aerial surveys of the Nezperce National Forest in Idaho revealed 138,692 acres of aerially visible top kill and tree mortality due to repeated defoliation by western spruce budworm, Choristoneura occidentalis Freeman.
A small ground sample indicates that up to 47 percent of the grand fir volume was affected by top...
Dwarf mistletoe is known to reduce both height and diameter growth and thus reduce the yield of an infested stand. This comparison of two similar stands--one healthy and the other infested--gives an indication of the impact of this parasite. The healthy stand has produced 1.5 times the board foot volume...
Numerous stands of western larch, Larix occidentalis, on the St. Joe, Coeur d'Alene, and Kaniksu National Forests, Idaho, show signs of gradual deterioration following repeated defoliation by larch casebearer, Coleophora Zaricella Hbn. (Tunnock et al. 1969). Stand deterioration can occur after 4 years of continued heavy defoliation. The main symptom...
The benomyl fungicide, rersan, applied at 7 and 14 pounds active ingredient per acre, on April 26 and July 25, 1973, was ineffective in reducing mortality in 2-0 Engelmann spruce seedlings derived from two different seed sources growing in three different nursery sections at the USFS Coeur d'Alene Nursery. Percent...
Eradication of Ribes spp. to control white pine blister rust in Yellowstone National Park was started in 1947. In 1968 this study was initiated to evaluate the previous control effort. Ribes eradication was suspended in 1968 in 18 white pine stands and Ribes and rust were allowed to increase within...
Needlecast fungi were found on 95 percent of damage collections in a June survey of Scots pine (Pinus sylvestris) Christmas tree plantations in the Kalispell Basin western Montana. Western gall rust (Endocronartium harknessii) and pine bark aphids (Pineus sp.) were present on 6.6 and 2.5 percent of collections, respectively. Cylcaneusma...
Mortality from various causes was recorded in a Douglas-fir tussock moth, Orgyia pseudotsugata McD., outbreak southeast of Coeur d'Alene, Idaho, in 1974. Observations began June 27 when about 50 percent of the larvae were second instars and continued until pupation. Within a 35-day period, there was a 93 percent average...
Mountain pine beetle populations increased in 1979 in the Thompson River drainage to levels predicted following the 1978 attack period. New attacks in 1979 averaged 27 per acre. Current estimates indicate another 25 percent of the remaining lodgepole pine could be killed in 1980.
This report contains an overview of the present mountain pine beetle infestation in lodgepole pine stands on Federal, State, and private lands on the Plains Ranger District. Particular emphasis is placed on the potential for beetle mortality in the Thompson River drainage where recent ground surveys show more than 21...
The mountain pine beetle reached epidemic levels in second-growth 80-yearold ponderosa pine stands on the Ninemile Ranger District in 1969. The
outbreak increased through 1971 and spread over 30,000 acres. Heavy
infestation occurred on about 2,600 acres within this area. A two-stage
survey was used during 1972 and 1973 to...
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...
Two thousand and thirty-nine trees on 213 plots are being monitored yearly for
root disease infection and mortality. Three compartments on the Fernan Ranger
District of the Idaho Panhandle National Forests are the site of the project.
Relationships between factors such as species, aspect, slope, elevation,
habitat type, stand appearance...
The pine needle cast fungus, Lophodermella concolor, caused severe discoloration and subsequent defoliation of lodgepole pine on over 4,000 acres and light defoliation on over 4,500 acres of lodgepole pine in the lower Clark Fork River drainage in 1975. Some trees had lost the last 3 years' growth of needles,...
An evaluation was made during midsummer 1972 to measure damage by the carpenterworm, Prionoxystus robiniae, and the ash borer, Podosesia syringae, to green ash in windbreaks in North Dakota. Intensity of infestation was determined in four land resource areas and four age classes of windbreaks. Of the 96 windbreaks examined...
A study was conducted in summer of 1973 to assess impact of fluoride-insect damage on radial growth of lodgepole pine near the Anaconda Aluminum Company at Columbia Falls, Montana. Statistically significant growth losses attributed primarily to the effects of fluorides were found in 40 14 of 17 unmanaged stands for...
Evaluation of Douglas-fir tussock moth, Orgyia pseudotsugata, egg masses collected from an outbreak area in the lower Flathead Valley indicated that overall egg viability was relatively high, egg parasitism was low, and virus infestation averaged 7.1 percent northwest of Polson, 17.9 percent south of St. Ignatius, and 57.0 percent west...
Douglas-fir tussock moth egg mass studies during winter 1974 indicate that natural factors such as low egg viability, egg parasitism, and virus do not alter the potential for heavy defoliation in two sections south of Frenchtown and one section northwest of Lolo, Montana.
Preliminary analysis of data from this study in the mountains southwest of the Anaconda Copper Smelter, an industrial source of SO2 and heavy metal particulate, reflects a complex pattern of pollutant impact. The differential effect of smelter emissions on plant life in the study area is best explained by the...
The lodgepole pine type commonly occurs as an even-aged, singlestoried, and overstocked forest. Dwarf mistletoe is widespread throughout the type and causes growth and quality reduction, reduced seed production, and some direct mortality. The land manager has three alternatives where dwarf mistletoe occurs: (1) do nothing, (2) eradicate the stand,...