Phoretic mite associates of mountain pine beetle at the leading edge of an infestation in northwestern Alberta, Canada

2011 ◽  
Vol 143 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Boyd A. Mori ◽  
Heather C. Proctor ◽  
David E. Walter ◽  
Maya L. Evenden

AbstractWe identified species of mites phoretically associated with mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), collected from bolts of lodgepole pine, Pinus contorta Douglas ex Louden (Pinaceae), and pheromone-baited traps in northwestern Alberta, Canada. Mite load and species composition were compared between beetle sexes and with beetle emergence time and estimated body size. The vast majority of mites associated with D. ponderosae in Alberta belonged to three species: Proctolaelaps subcorticalis Lindquist (Acari: Mesostigmata: Melicharidae), Histiogaster arborsignis Woodring (Acari: Astigmatina: Acaridae), and Tarsonemus ips Lindquist (Acari: Prostigmata: Tarsonemidae). There was no difference in mite loads on male and female beetles recovered from bolts in the laboratory and those from pheromone-baited traps in the field. More mites were found on larger beetles in the laboratory, but only T. ips showed this pattern on field-trapped beetles. There was no relationship between total mite load or load by mite species and beetle emergence time in the laboratory, but total mite load on field-trapped beetles decreased over the collecting season (10 June – 3 September 2009) at five collection locations (Grovedale, Blueberry Mountain, Hythe, Evergreen Park, and Glenleslie). This study is the first to document the assemblage of phoretic mites on D. ponderosae in Alberta and will help to direct future research on their interactions.


2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons

Extensive outbreaks of the mountain pine beetle ( Dendroctonus ponderosae Hopkins) will alter the structure of many stands that will likely be attacked again before experiencing a stand-replacing fire. We examined a stand of lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) in Grand Teton National Park currently experiencing a moderate-level outbreak and previously attacked by mountain pine beetle in the 1960s. Consistent with published studies, tree diameter was the main predictor of beetle attack on a given tree, large trees were preferentially attacked, and tree vigor, age, and cone production were unimportant variables for beetle attack at epidemic levels. Small trees killed in the stand were killed based mainly on their proximity to large trees and were likely spatially aggregated with large trees as a result of the previous outbreak. We concluded that the driving factors of beetle attack and their spatial patterns are consistent across outbreak severities but that stand structure altered by the previous outbreak had implications for the current outbreaks in the same location. This study should catalyze additional research that examines how beetle-altered stand structure affects future outbreaks — an important priority for predicting their impacts under climate change scenarios that project increases in outbreak frequency and extent.



1989 ◽  
Vol 121 (6) ◽  
pp. 521-523 ◽  
Author(s):  
A.J. Stock ◽  
R.A. Gorley

The mountain pine beetle, Dendroctonus ponderosae Hopk., causes extensive mortality of lodgepole pine, Pinus contorta var. latifolia Engelm., throughout western North America (Van Sickle 1982). The Prince Rupert Forest Region, in the northwest of British Columbia, initiated an aggressive beetle management program in 1981. Logging of infested stands, and winter felling and burning of individual infested trees are the most common direct control techniques.The “Bristol Lake” infestation developed in the Bulkley Forest District, approximately 55 km northwest of Smithers, B.C., on a steep rocky ridge within the valley of Harold Price Creek. The area contained large volumes of mature lodgepole pine, and control of the infestation was therefore considered critical to the local beetle management plan, but the size (50 ha) and rough topography of the infested area precluded normal direct control measures.



Author(s):  
W. Romme ◽  
J. Yavitt ◽  
D. Knight

A research project was initiated in 1980 to study the effects of outbreaks of the mountain pine beetle (Dendroctonus ponderosae Hopkins) on lodgepole pine forest (Pinus contorta Dougl. ssp. latifolia) in Yellowstone National Park and surrounding areas. This native insect apparently has long been associated with lodgepole pine, and reports of small numbers of beetles can be found in Park records as early as 1925. However, in the late 1940's and early 1950's major outbreaks began to occur on the Caribou and Targhee National Forests immediately to the west and southwest of Yellowstone and Grand Teton National Parks. An outbreak in Grand Teton National Park and the adjacent Teton National Forest began in the 1950's, with an explosive increase in 1961 followed by an eventual subsidence in the late 1960's. The first major outbreak in Yellowstone National Park began in the late 1960's in the Bechler and South Entrance areas, reaching a peak there in 1970 and later declining. Yearly aerial surveys conducted thereafter showed a steady northward movement of the outbreak through the western half of the Park at a rate of 1 - 5 km per year. By 1978 the peak outbreak was centered around West Yellowstone, with hundreds of infested trees per hectare. The outbreak is now moving north and east along the Madison and Gibbon Rivers, with the greatest beetle populations currently in the vicinity of Madison Junction.



2006 ◽  
Vol 82 (4) ◽  
pp. 579-590 ◽  
Author(s):  
John H Borden ◽  
Anna L Birmingham ◽  
Jennifer S Burleigh

Experiments were conducted near Williams Lake and Quesnel, BC in 2003 to evaluate the effectiveness of the anti-aggregation pheromone verbenone and a three-component non-host volatile (NHV) blend (E-2- and Z-3-hexen-1-ol and benzyl alcohol) in deterring attack of lodgepole pines, Pinus contorta var. latifolia Engelmann, by the mountain pine beetle, Dendroctonus ponderosae Hopkins. In 0.16-ha square plots, with a pheromone-baited tree in the centre and 16 release points at 10-m centres, either verbenone (in a polyurethane gel inside plastic membrane pouches, released at ca. 100 mg/day) or the NHVs (released from separate bubble caps at ca. 1.2 mg/day) deterred attack, but efficacy was not increased by combining them. When deployed from 25 release points at 10-m centres in 0.25-ha square plots, verbenone plus NHVs were effective in deterring attack in some (but not all) cases, when compared to attack in a 25-m wide band around the treated zone. In a test of the push-pull tactic, verbenone plus the NHV blend were tested in a 10-replicate experiment with 100, 44.4 or 25 release points/ha at 10-, 15- or 20-m centres, respectively, in a 1-ha square central zone surrounded by a 3-ha, 50-m-wide band containing 12 pheromone-baited lodgepole pines 50 m apart. Other treatments were pheromonebaited trees alone, and an untreated control. In the three push-pull treatments (but not the bait only or control treatments), 28 of 30 replicates had significantly more mass-attacked trees in the pheromone-baited outer 3 ha than in the inner ha treated with verbenone plus NHVs. The percentage of available trees ≥ 17.5 cm diameter at breast height (dbh) that were mass-attacked was < 10% in 5, 4 and 3 of 10 replicates when verbenone plus NHVs were deployed at 10-, 15- and 20-m centres, respectively, and was < 10% in two each of the bait only and control replicates. The mean ratios of newly-attacked green trees in 2003 to red trees killed in 2002 were significantly lower in the inner ha of the 10-m and 15-m centre treatments (2.6 and 2.7, respectively) than 5.9 in the untreated control. Also the pooled percentages of attacked trees that were not mass-attacked were significantly higher in the inner ha of the treatments with centres at 15 m (24.7%) and 10 m (17.6%) than in the other three treatments (all between 12% and 13%). Despite the apparent efficacy in 10-m and 15-m centre treatments, some replicates failed spectacularly. Failure was not significantly related to the incidence of red trees, but was negatively related to density/ha of available trees and positively related to mean dbh. We recommend operational implementation of the push-pull tactic at 10-m or 15-m centres when the density of available lodgepole pines is > 400/ha, the mean dbh is ≤ 25 cm, current attack is ≤ 15%, and the tactic is part of an integrated pest management program that includes sanitation harvesting. Using verbenone alone at 15-m centres would cost $380/ha (CAD), excluding labour. Key words: mountain pine beetle, Dendroctonus ponderosae, lodgepole pine, Pinus contorta var. latifolia, pheromones, semiochemicals, pest management



2013 ◽  
Vol 91 (4) ◽  
pp. 235-244 ◽  
Author(s):  
A.J. Fleming ◽  
A.A. Lindeman ◽  
A.L. Carroll ◽  
J.E. Yack

Acoustic signaling is widespread in bark beetles (Scolytinae), although little is known about the physical characteristics of signals, how they are transmitted, and how they differ among behavioural contexts. Signals were studied in the male mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) during stress, male–female, and male–male interactions. Sounds are broadband with significant energy in the ultrasound (peaks between 15 and 26 kHz) and low amplitude (55 and 47 dB SPL at 2 and 4 cm, respectively), indicating that signaling functions at close range. Signal trains vary among contexts primarily in the proportions of chirp types. Chirps were categorized as being simple or interrupted, with the former having significantly lower tooth strike rates and shorter chirp durations. Stress chirps are predominantly simple with characteristics resembling other insect disturbance signals. Male–female interactions begin with the male producing predominantly interrupted chirps prior to gallery entrance, followed by simple chirps. Male–male (rivalry) chirps are predominantly simple, with evidence of antiphonal calling. Substrate-borne vibrations were detectable with a laser-doppler vibrometer at short distances (1–3 cm), suggesting that sensory organs could be tuned to either air or substrate-borne vibrations. These results have important implications for future research on the function and reception of acoustic signals in bark beetles.



2009 ◽  
Vol 39 (4) ◽  
pp. 839-848 ◽  
Author(s):  
V.G. Nealis ◽  
M.K. Noseworthy ◽  
R. Turnquist ◽  
V.R. Waring

The effect of removing lodgepole pine ( Pinus contorta Dougl. ex Loud.) and retaining Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) to reduce the risk of disturbance from mountain pine beetle ( Dendroctonus ponderosae Hopk.) in mixed conifer stands in southern British Columbia, Canada, on population processes influencing outbreaks of western spruce budworm ( Choristoneura occidentalis Free.) was evaluated in 10 paired (open vs. closed) field plots. Overall feeding damage to Douglas-fir was significantly, but only slightly, lower in open stands compared with closed stands. Although open plots tended to recruit more budworms, the losses resulting from the dispersal of spring-emerging budworms in search of feeding sites were significantly greater in open plots. The forest management benefits of these early season losses were mitigated, however, by more mortality of budworms from natural enemies, particularly diseases, in the closed plots during the budworm feeding period. These results are discussed in terms of compensating population processes and balancing objectives in forest pest management. In this case, selective harvesting of lodgepole pine as a mitigation strategy for the mountain pine beetle conserved the midterm timber supply potential represented by associated Douglas-fir even in the presence of an outbreak of the western spruce budworm.



1985 ◽  
Vol 117 (11) ◽  
pp. 1445-1446 ◽  
Author(s):  
Charles E. Richmond

The mountain pine beetle, Dendroctonus ponderosae Hopkins, is one of the most destructive bark beetles found on pine in western North America (McCambridge et al. 1979), particularly in forests of lodgepole pine, Pinus contorta Douglas var. latifolia (Furniss and Carolin 1977). The treatment registered in the United States for the protection of high-value trees in residential areas and recreational areas is 2% carbaryl applied to the bole of the tree with a hydraulic sprayer. Recently, pine oil, a derivative of paper pulp waste, was found to be an effective non-insecticidal repellent against several species of bark beetles (Nijholt et al. 1981).



2000 ◽  
Vol 15 (4) ◽  
pp. 183-188 ◽  
Author(s):  
J.C. Vandygriff ◽  
L.A. Rasmussen ◽  
J.F. Rineholt

Abstract A multiyear study of synthesized mountain pine beetle (Dendroctonus ponderosae) pheromones was conducted within lodgepole pine (Pinus contorta) stands on the Sawtooth National Recreation Area to demonstrate their potential use as a management tool for fuelwood harvest. The use of mountain pine beetle aggregant baits was shown to be highly effective in relocating beetles into designated bait blocks, dramatically increasing the amount of beetle-related tree mortality. Treatment of blocks with antiaggregant verbenone capsules appeared to provide little or no additional protection when compared with associated control blocks. Given defined objectives and appropriate stand and insect population conditions, pheromone baits can be used to improve management of fuelwood harvest and potentially improve stand health. West. J. Appl. For. 15(4):183–188.



1987 ◽  
Vol 65 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H. S. Whitney ◽  
R. J. Bandoni ◽  
F. Oberwinkler

A new basidiomycete, Entomocorticium dendroctoni Whitn., Band. & Oberw., gen. et sp. nov., is described and illustrated. This cryptic fungus intermingles with blue stain fungi and produces abundant essentially sessile basidiospores in the galleries and pupal chambers of the mountain pine bark beetle (Dendroctonus ponderosae Hopkins Coleoptera: Scolytidae) in lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.). The insect apparently disseminates the fungus. Experimentally, young partially insectary reared adult beetles fed E. dendroctoni produced 19% more eggs than beetles fed the blue stain fungi.



Sign in / Sign up

Export Citation Format

Share Document