scholarly journals Within-Stand Distribution of Tree Mortality Caused by Mountain Pine Beetle, Dendroctonus ponderosae Hopkins

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 112 ◽  
Author(s):  
José F. Negrón
Keyword(s):  
Ponderosa Pine ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Dendroctonus Ponderosae ◽  
Small Scale ◽  
Mountain Pine Beetles ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pine Beetles ◽  
Stand Conditions

The mountain pine beetle (MPB) (Dendroctonus ponderosae) is a bark beetle that attacks and kills ponderosa pine (Pinus ponderosa), among other pine species throughout the western conifer forests of the United States and Canada, particularly in dense stands comprising large trees. There is information on the stand conditions that the insect prefers. However, there is a paucity of information on how small-scale variation in stand conditions influences the distribution of tree mortality within a stand. I examined the small-scale distribution of ponderosa pine basal area pre- and post a mountain pine beetle infestation, and used geostatistical modeling to relate the spatial distribution of the host to subsequent MPB-caused tree mortality. Results indicated increased mortality in the denser parts of the stand. Previous land management has changed historically open low-elevation ponderosa pine stands with aggregated tree distribution into dense stands that are susceptible to mountain pine beetles and intense fires. Current restoration efforts are aimed at reducing tree density and leaving clumps of trees, which are more similar to historical conditions. The residual clumps, however, may be susceptible to mountain pine beetle populations. Land managers will want to be cognizant of how mountain pine beetles will respond to restoration treatments, so as to prevent and mitigate tree mortality that could negate restoration efforts.

Radar observation and aerial capture of mountain pine beetle, Dendroctonus ponderosae Hopk. (Coleoptera: Scolytidae) in flight above the forest canopy

2008 ◽  
Vol 38 (8) ◽  
pp. 2313-2327 ◽  
Author(s):  
Peter L. Jackson ◽  
Dennis Straussfogel ◽  
B. Staffan Lindgren ◽  
Selina Mitchell ◽  
Brendan Murphy
Keyword(s):  
Mountain Pine Beetle ◽  
Forest Canopy ◽  
Dendroctonus Ponderosae ◽  
Weather Radar ◽  
Mountain Pine Beetles ◽  
Emergence Period ◽  
Transport Distance ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pine Beetles

An outbreak of the mountain pine beetle ( Dendroctonus ponderosae Hopk.) in central British Columbia, Canada, has reached an unprecedented size and intensity and has been spreading. The 2005 emergence and subsequent flight of mountain pine beetle was studied using direct observation of emergence, weather radar imagery, and aerial capture. To verify that the daytime, clear-air radar returns seen during this period were indeed generated by airborne mountain pine beetles, aerial sampling in the area covered by the radar was performed using a drogue capture net towed by a single-engine light aircraft. Results verify that airborne mountain pine beetles are being detected by the weather radar and that, during the emergence period, significant numbers of mountain pine beetles can be found at altitudes up to more than 800 m above the forest canopy. An estimate of transport distance indicates that mountain pine beetles in flight above the forest canopy may move 30–110 km·day–1. An estimate of the instantaneous density of mountain pine beetles in flight above the canopy on flight days in 2005 indicate a mean (maximum) density of 4950 (18 600) beetles·ha–1.

PRIMARY ATTRACTION OF MOUNTAIN PINE BEETLE, DENDROCTONUS PONDEROSAE HOPK. (COLEOPTERA: SCOLYTIDAE), TO BOLTS OF LODGEPOLE PINE

1991 ◽  
Vol 123 (2) ◽  
pp. 299-304 ◽  
Author(s):  
Henry A. Moeck ◽  
Clarence S. Simmons
Keyword(s):  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Dendroctonus Ponderosae ◽  
Field Tests ◽  
Mountain Pine Beetles ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Primary Attraction ◽  
Pine Beetles ◽  
Empty Control

AbstractThree field tests were conducted in which fresh lodgepole pine (Pinus contorta Douglas var. latifolia Engl.) material, namely bolts with and without bark, bark only, and freshly tapped resin, were placed in beetle-excluding “greenhouse” cages; empty cages served as controls. Two “window” flight traps per cage, at right angles to each other, caught mountain pine beetles (Dendroctonus ponderosae Hopkins) arriving at the cages. Significantly more mountain pine beetles were trapped at cages baited with bolts and wood only than at empty control cages. Primary attraction in the mountain pine beetle is thus established, in the absence of pheromones and normal visual cues (tree stem silhouette). More beetles were trapped at cages baited with bark only and with resin than at empty control cages, but differences were not significant at p = 0.05. The sex ratio of trapped beetles (4.83 females: 1 male) was more than twice as high as the reported sex ratios of free-flying and emerging beetles.

THE RELATIONSHIP BETWEEN DENSITY OF EMERGED DENDROCTONUS PONDEROSAE (COLEOPTERA: SCOLYTIDAE) AND DENSITY OF EXIT HOLES IN LODGEPOLE PINE

1985 ◽  
Vol 117 (3) ◽  
pp. 267-275 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton
Keyword(s):  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Latex Paint ◽  
Mountain Pine Beetles ◽  
Emergence Period ◽  
South Central ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pine Beetles ◽  
The Relationship

AbstractThe relationship between the density of insect holes in the bark (X1) and the density of emerged mountain pine beetles (Y) was investigated in naturally infested lodgepole pine in south-central British Columbia. The density of exit and ventilation holes (Ho) that were present in the bark prior to emergence by mountain pine beetle averaged 10% of all holes present following the emergence period. There was a weak but significant inverse relationship between Ho and both phloem thickness and density of emerged mountain pine beetles. Painting the bark with light-color latex paint did not affect survival or the temporal pattern of emergence by mountain pine beetle but ensured identification and greatly enhanced counting of fresh exit holes. Of the several regression models investigated, the relation between Y and both X1 and X2 (= X1 – Ho) was best fitted by a log-log linear model. A method is suggested for setting limits on the size of exit holes cut by mountain pine beetle in order to exclude from X2 much of the variation caused by exit holes cut by associated insects. A simple mathematical model was developed of the relationship between mean density of exit holes and the density of emerged mountain pine beetles.

Evaluation of Stem-Injected TREE-äge® (4% Emamectin Benzoate) for Protecting Western White Pines (Pinus monticola) from Mountain Pine Beetle (Dendroctonus ponderosae Hopkins)(Coleoptera: Curculionidae: Scolytinae)

2020 ◽  
Vol 46 (5) ◽  
pp. 333-346
Author(s):  
Joseph Doccola ◽  
Sheri Smith ◽  
Joseph Fischer ◽  
Brian Strom
Keyword(s):  
Bark Beetles ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Dendroctonus Ponderosae ◽  
Pathogenic Fungi ◽  
Tree Age ◽  
Pinus Monticola ◽  
Emamectin Benzoate ◽  
Mountain Pine ◽  
Pine Beetle

The protection of high-value trees against bark beetles and the development of alternatives to bole sprays is a priority for the tree manager. The objective of this study was to evaluate stem-injected TREE-äge® (emamectin benzoate [EB]) as a protective treatment for western white pines (Pinus monticola Dougl. ex D. Don) against mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins). Treatment efficacy was based solely on tree mortality as per Shea protocols (i.e., ≥ 60% check vs. ≤ 20% treated tree mortality). Our first experiment was installed in 2007 and included trees stem-injected with TREE-äge and untreated controls. Bole application of S-(-)-verbenone and green leaf volatile (GLV) blend was included for observational comparison. Pressure from MPB was heavy, as indicated by the number and timing of control tree mortality (90%). Strip attacks by MPB in TREE-äge trees indicated that the impacts of EB, and by inference its distribution, were inconsistent. In 2009, the injection protocol was revised to improve EB distribution in the phloem via closer injection points. In the 2009 TREE-äge-treated trees, adult beetle mining stopped when they contacted phloem and was insufficient to cause tree death by girdling. Blue-stain fungi colonized the sapwood of trees in both studies. Isolates from autopsied trees treated with TREE-äge alone were subsequently identified as Grosmannia clavigera and Leptographium longiclavatum (Ophiostomatales: Ascomycota), species that can incite tree mortality. In 2013, we revised our protocol to include GLV plus verbenone or propiconazole with TREE-äge, wherein these treatments proved effective in protecting trees against MPB and their associated pathogenic fungi.

A comparison of mycangial and phoretic fungi of individual mountain pine beetles

2003 ◽  
Vol 33 (7) ◽  
pp. 1331-1334 ◽  
Author(s):  
Diana L Six
Keyword(s):  
Mountain Pine Beetle ◽  
External Surface ◽  
Ophiostomatoid Fungi ◽  
Cross Contamination ◽  
Mountain Pine Beetles ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Pine Beetles ◽  
Ophiostoma Montium ◽  
Ophiostomatoid Fungus

Two ophiostomatoid fungi, Ophiostoma clavigerum (Robinson-Jeffrey & Davidson) Harrington and Ophiostoma montium (Rumbold) von Arx, are known to be associated with the mycangia of the mountain pine beetle, Dendroctonus ponderosae Hopkins. However, virtually nothing is known regarding the phoretic fungi carried on the external surface of the exoskeleton of this beetle. In this study, I compared the phoretic fungi of individual D. ponderosae with the fungi carried in their mycangia. As many beetles carried ophiostomatoid fungi on the exoskeleton as in the mycangia; however, the species of ophiostomatoid fungus carried phoretically on an individual beetle was not always the same as was carried in its mycangia. Ophiostoma montium was isolated more often from exoskeletal surfaces than from mycangia, while the reverse was true for O. clavigerum. It appears that O. clavigerum is highly adapted for mycangial dissemination, while O. montium is adapted to phoretic as well as mycangial dissemination. Ophiostoma ips (Rumbold) Nannf. was phoretic on two beetles, indicating that cross-contamination with fungi from cohabiting Ips spp. may sometimes occur. Several non-ophiostomatoid fungi were isolated from exoskeletal surfaces, but none consistently so. All non-ophiostomatoid fungi isolated were common saprophytes often found in beetle-killed trees. Yeasts were also common and were isolated more often from the exoskeleton than from mycangia.

scholarly journals Patterns of Diversity in the Symbiotic Mite Assemblage of the Mountain Pine Beetle, Dendroctonus Ponderosae Hopkins

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1102
Author(s):  
Sneha Vissa ◽  
Javier E. Mercado ◽  
Danielle Malesky ◽  
Derek A. Uhey ◽  
Boyd A. Mori ◽  
...  
Keyword(s):  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Insect Pests ◽  
Species Turnover ◽  
Dendroctonus Ponderosae ◽  
Coniferous Forest ◽  
Host Tree ◽  
Local Climate ◽  
Mountain Pine ◽  
Pine Beetle

The mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Scolytinae), is an economically important bark beetle species with a wide geographic range spanning from the southwestern United States into northern Canada. This beetle causes extensive tree mortality to 13 pine species. Mites (Acari) are common and abundant symbionts of mountain beetles that may influence their fitness through positive and negative interactions. We present a unique assessment of the mite associates of mountain pine beetles using measures of alpha and beta diversity. We sampled phoretic mites from five beetle populations: Arizona, Colorado, South Dakota, Utah (USA), and Alberta (Canada) that varied in host tree species, local climate, and beetle population level. We collected 4848 mites from 8 genera and 12 species. Fifty to seventy percent of beetles carried mites in flight with the highest mite loads occurring in middle and southern populations; decreasing in northern populations. Mite assemblages (i.e., both richness and composition) varied along a south to north latitudinal gradient and were driven by species turnover (i.e., species replacement). Differences in mite composition increased with distance between populations. We discuss climatic variation, environmental filtering, and host tree differences as factors that could affect differences in mite composition between beetle populations and discuss implications for functional shifts. Our results could represent a model for estimating diversity patterns of mite symbionts associated with other major insect pests in coniferous forest systems.

Efficacy of verbenone in reducing lodgepole pine infestation by mountain pine beetles in Idaho

1989 ◽  
Vol 19 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Gene D. Amman ◽  
Ralph W. Thier ◽  
Mark D. McGregor ◽  
Richard F. Schmitz
Keyword(s):  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
National Forest ◽  
Significant Treatment ◽  
Mountain Pine Beetles ◽  
Mountain Pine ◽  
Fold Reduction ◽  
Significant Difference ◽  
Pine Beetle ◽  
Pine Beetles

Verbenone, a bark beetle antiaggregative pheromone, was deployed in lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) stands in the Sawtooth National Forest, Idaho, U.S.A., to test its efficacy in reducing tree losses to mountain pine beetle (Dendroctonusponderosae Hopkins). Treatments tested were verbenone, mountain pine beetle tree bait, verbenone plus mountain pine beetle tree bait, and a control. Each treatment was applied individually to 1-ha blocks and replicated four times. Treatment effects were measured by percentage of infested (i.e., mass-attacked) lodgepole pine. ANOVA showed a significant treatment effect (P < 0.005). Blocks treated with mountain pine beetle tree baits had significantly (P < 0.002) higher average percentages of infested trees (24.4%), whereas no significant difference occurred in percentages of infested trees among the other three treatments. Average percentages of infested trees were 0.9% for verbenone, 7.4% for verbenone plus mountain pine beetle tree bait, and 3.3% for the control. A 2.3-fold reduction in infested trees occurred when verbenone was applied to blocks treated with mountain pine beetle tree baits.

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