			Home About us Contact

Mountain Pine Beetle (mountain + pine_beetle)

Distribution by Scientific Domains

Life Sciences	87%

Selected Abstracts

A NOVEL METHOD OF FITTING SPATIO-TEMPORAL MODELS TO DATA, WITH APPLICATIONS TO THE DYNAMICS OF MOUNTAIN PINE BEETLES

NATURAL RESOURCE MODELING, Issue 4 2008
JUSTIN HEAVILIN
Abstract We develop a modular landscape model for the mountain pine beetle (Dendroctonus ponderosae Hopkins) infestation of a stage-structured forest of lodgepole pine (Pinus contorta Douglas). Beetle attack dynamics are modeled using response functions and beetle movement using dispersal kernels. This modeling technique yields four model candidates. These models allow discrimination between four broad possibilities at the landscape scale: whether or not beetles are subject to an Allee effect at the landscape scale and whether or not host selection is random or directed. We fit the models with aerial damage survey data to the Sawtooth National Recreation Area using estimating functions, which allows for more rapid and complete parameter determination. We then introduce a novel model selection procedure based on facial recognition technology to compliment traditional nonspatial selection metrics. Together with these we are able to select a best model and draw inferences regarding the behavior of the beetle in outbreak conditions. [source]

Protection of lodgepole pines from mass attack by mountain pine beetle, Dendroctonus ponderosae, with nonhost angiosperm volatiles and verbenone

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2001
D.P.W. Huber
Abstract A number of angiosperm nonhost volatiles (NHVs) and green leaf volatiles (GLVs) were tested alone and as supplements to the antiaggregation pheromone, verbenone, for their ability to disrupt attack by the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae), on lodgepole pine, Pinus contorta Dougl. ex Loud. var. latifolia Engel. Preliminary experiments led to a refined NHV blend [benzyl alcohol, guaiacol, benzaldehyde, nonanal, salicylaldehyde, and conophthorin] and a refined GLV blend [(Z)-3-hexen-1-ol and (E)-2-hexen-1-ol]. In a 20-replicate experiment, NHV and GLV groups both singly, and verbenone alone, significantly reduced MPB mass attack on pheromone-baited trees and on trees within 5 m of the pheromone-baited trees. Both blends in combination with verbenone reduced the number of mass attacked, baited trees to three out of 20 compared to 20 out of 20 of the baited controls. Each binary combination was also effective at reducing mass attack. In these experiments, all tested repellents were released from devices stapled to trees at the same point as the pheromone bait, suggesting that the repellency could have been to a point source, rather than to the whole tree. Therefore, in two further experiments bands of release devices were wrapped around the treated trees and the pheromone bait was removed from the treated trees. In one experiment, when the aggregation pheromone bait was suspended between pairs of trees treated with the NHV blend plus GLV blend plus verbenone, only three out of 25 treated pairs had mass attack on at least one member of the pair. In the other 60-replicate experiment, with no pheromone baits present, attack occurred on 13 untreated and 11 banded trees, all in the path of a large advancing infestation. However, the mean attack density on the banded trees was significantly reduced to a level below the 40 attacks m,2 of bark surface required to kill a healthy lodgepole pine. As a result of these experiments, operational trials are recommended. [source]

Dose-dependent uptake, elimination, and toxicity of monosodium methanearsonate in adult zebra finches (Taeniopygia guttata)

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2008
Courtney A. Albert
Abstract Monosodium methanearsonate (MSMA), an arsenic-based pesticide, has been used for the past 10 years in attempts to suppress mountain pine beetle (Dendroctonus ponderosae) outbreaks in British Columbia, Canada. Previous studies have shown that cavity nesting forest birds such as woodpeckers forage and breed in MSMA treated pine stands. Here we examined the effects of MSMA in the laboratory using the zebra finch (Taeniopygia guttata), with the objective to examine tissue distribution and sublethal toxic effects in a model avian species. Zebra finches were exposed to this pesticide at doses similar to those found in bark beetle samples from MSMA stands of trees treated in the southern interior of British Columbia (8, 24, and 72 ,g/g/d and a control group). Results showed high excretion (>90%) of arsenic in all dose groups, as well as dose-dependent trends in accumulation of arsenic in the blood (p < 0.001) and specific tissues. Monomethylarsonic acid, MMA (V), was the predominant form of arsenic in the blood plasma. Dimethylarsinic acid was the major form of arsenic found in the liver (83%) and kidney (61%) tissues. The brain tissue contained primarily the MMA (V) form (57%). Significant weight loss occurred in the two highest dose groups (p < 0.05). Birds in the highest dose group lost up to 15% of initial body mass. [source]

Blister rust and western forest biodiversity: ecology, values and outlook for white pines

FOREST PATHOLOGY, Issue 3-4 2010
D. F. Tomback
Summary Eight white pine species are widely distributed among the forests of western Canada and the United States. The different forest communities with these species contribute biodiversity to the western landscape. The trees themselves provide various ecosystem services, including wildlife habitat and watershed protection. White pine communities range in elevation from lower to upper treeline, in successional stage from seral to climax, and in stand type from krummholz to closed-canopy forest. Many white pine species are moderately to strongly fire-dependent for regeneration; several species are extreme stress tolerators and persistent on harsh sites. Among the white pines are the oldest-living trees, the world's largest pines, species dependent on birds for seed dispersal, species important for grizzly bear habitat and species of high commercial timber value. The principal threats to white pine populations are blister rust (Cronartium ribicola, pathogen), fire suppression, succession, mountain pine beetle and climate change. Severe population declines in several white pine species are attributed to losses caused by these factors acting either alone or together, and sometimes in concert with logging and other land-use changes. The importance and particular interactions of these threats vary by region and species. For example, many northern and western populations of whitebark pine are seriously declining from a combination of mountain pine beetle outbreaks and severe blister rust infestations. As whitebark pines provide many keystone services on high-elevation sites, their loss would impact forest composition and structure, succession, biodiversity, and ecosystem services. Although there are serious challenges to science-based management and conservation (especially in remote American wilderness areas), prompt and effective intervention promoting regeneration of blister rust-resistant white pines could mitigate these severe impacts. [source]

Climate change and range expansion of an aggressive bark beetle: evidence of higher beetle reproduction in naïve host tree populations

JOURNAL OF APPLIED ECOLOGY, Issue 5 2010
Timothy J. Cudmore
Summary 1.,Hosts may evolve defences that make them less susceptible and suitable to herbivores impacting their fitness. Due to climate change-driven range expansion, herbivores are encountering naïve host populations with increasing frequency. 2.,Aggressive bark beetles are among the most important agents of disturbance in coniferous forest ecosystems. The presence of bark beetle outbreaks in areas with a historically unsuitable climate, in part a consequence of climate change, provided an opportunity to assess the hypothesis that the mountain pine beetle Dendroctonus ponderosae has higher reproductive success in lodgepole pine Pinus contorta trees growing in areas that have not previously experienced frequent outbreaks. 3.,We felled and sampled mountain pine beetle-killed trees from historically climatically suitable and unsuitable areas, i.e. areas with and without a historical probability of frequent outbreaks. Reproductive success was determined from a total of 166 trees from 14 stands. 4.,Brood productivity was significantly affected by climatic suitability class, such that mean brood production per female increased as historical climatic suitability decreased. 5.,Synthesis and applications. The current study demonstrates that the mountain pine beetle has higher reproductive success in areas where its host trees have not experienced frequent beetle epidemics, which includes much of the current outbreak area in north central British Columbia. This increased productivity of mountain pine beetle is likely to have been a key reason for the rapid population buildup that resulted in unprecedented host tree mortality over huge areas in western Canada. The outbreak thus provides an example of how climate change-driven range expansion of native forest insects can have potentially disastrous consequences. Since an increased reproductive success is likely to accelerate the progression of outbreaks, it is particularly critical to manage forests for the maintenance of a mosaic of species and age classes at the landscape level in areas where host tree populations are naïve to eruptive herbivores. [source]

Successful colonization, reproduction, and new generation emergence in live interior hybrid spruce Picea engelmannii×glauca by mountain pine beetle Dendroctonus ponderosae

AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009
Dezene P. W. Huber
Abstract 1,Although mountain pine beetle Dendroctonus ponderosae Hopkins are able to utilize most available Pinus spp. as hosts, successful colonization and reproduction in other hosts within the Pinaceae is rare. 2,We observed successful reproduction of mountain pine beetle and emergence of new generation adults from interior hybrid spruce Picea engelmannii×glauca and compared a number of parameters related to colonization and reproductive success in spruce with nearby lodgepole pine Pinus contorta infested by mountain pine beetle. 3,The results obtained indicate that reduced competition in spruce allowed mountain pine beetle parents that survived the colonization process to produce more offspring per pair than in more heavily-infested nearby pine. 4,We also conducted an experiment in which 20 spruce and 20 lodgepole pines were baited with the aggregation pheromone of mountain pine beetle. Nineteen pines (95%) and eight spruce (40%) were attacked by mountain pine beetle, with eight (40%) and three (15%) mass-attacked, respectively. 5,Successful attacks on nonhost trees during extreme epidemics may be one mechanism by which host shifts and subsequent speciation events have occurred in Dendroctonus spp. bark beetles. [source]