Stimulation of Resinosis and Apparent Inhibition of Blue Stain Development in Ponderosa Pine by Paraquat

1979 ◽  
Vol 25 (4) ◽  
pp. 569-575
Author(s):  
Frank Kidd ◽  
C. P. P. Reid

Abstract The effects of stemfrill application of paraquat solution concentration (1, 8, 16, and 30 percent), volume (5, 10, and 20 ml), and date of application (8-9 July and 21-22 August) on resinosis in sapwood of Pinus ponderosa were evaluated. The greatest yield of extractives resulted from treatment with 10 ml of an 8 percent solution applied 8-9 July. No qualitative changes in oleoresin composition attributable to paraquat application were detected by gas-liquid chromatography of the terpene fraction. Blue stain development was inhibited above treatment frills. This inhibition was greatest following treatment with 20 ml of 8 percent paraquat applied on 8-9 July. Growth of Ceratocystis montia, a fungal symbiont of the mountain pine beetle was prevented by paraquat at concentrations above 5 ppm in malt-agar medium. Forest Sci. 25:569-575.

2012 ◽  
Vol 42 (12) ◽  
pp. 2022-2036 ◽  
Author(s):  
Ryan S. Davis ◽  
Sharon Hood ◽  
Barbara J. Bentz

Bark beetles can cause substantial mortality of trees that would otherwise survive fire injuries. Resin response of fire-injured northern Rocky Mountain ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and specific injuries that contribute to increased bark beetle attack susceptibility and brood production are unknown. We monitored ponderosa pine mortality and resin flow and bark beetle colonization and reproduction following a prescribed fire in Idaho and a wildfire in Montana. The level of fire-caused tree injury differed between the two sites, and the level of tree injury most susceptible to bark beetle attack and colonization also differed. Strip-attacked trees alive 3 years post-fire had lower levels of bole and crown injury than trees mass attacked and killed by bark beetles, suggesting that fire-injured trees were less well defended. Brood production of western pine beetle ( Dendroctonus brevicomis LeConte) did not differ between fire-injured and uninjured trees, although mountain pine beetle ( Dendroctonus ponderosae Hopkins) brood production was low in both tree types, potentially due to competition with faster developing bark beetle species that also colonized trees. Despite a large number of live trees remaining at both sites, bark beetle response to fire-injured trees pulsed and receded within 2 years post-fire, potentially due to a limited number of trees that could be easily colonized.


2005 ◽  
Vol 137 (3) ◽  
pp. 367-375 ◽  
Author(s):  
Donald R. Owen ◽  
David L. Wood ◽  
John R. Parmeter

AbstractThe host-colonization behavior of the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Scolytidae), was investigated in stands of ponderosa pine, Pinus ponderosa P. & C. Lawson (Pinaceae), with black stain root disease in the central Sierra Nevada of California. By felling live trees, we found that trees with pitch tubes produced during the initiation of tunneling by D. valens had a significantly higher incidence of black stain root disease, caused by Leptographium wageneri var. ponderosum (Harrington et Cobb), than trees without pitch tubes. Trees with the most D. valens pitch tubes had the greatest likelihood of being diseased. Additionally, observations over a 3-year period revealed that trees with D. valens pitch tubes had a significantly higher mortality rate than trees without pitch tubes. Infection by L. wageneri was confirmed for most of the trees that died, and death typically did not occur without mass attacks by the western pine beetle, D. brevicomis LeConte, and (or) the mountain pine beetle, D. ponderosae Hopkins. Trees with the most D. valens pitch tubes had the highest mortality rate. An experiment was conducted to compare the attraction of D. valens and other insects to wounded-diseased, wounded-symptomless, and unwounded trees. More D. valens, Spondylis upiformis Mannerheim (Coleoptera: Cerambycidae), and Hylastes spp. (Coleoptera: Scolytidae) were attracted to wounded trees than to unwounded trees. Catches of these beetles on wounded-diseased trees were not significantly different from catches on wounded-symptomless trees.


2011 ◽  
Vol 41 (5) ◽  
pp. 1031-1046 ◽  
Author(s):  
Chris J.K. MacQuarrie ◽  
Barry J. Cooke

Thinning, the selective removal of some trees from a forest, is one way forest managers can reduce the probability that a forest will be susceptible to attack by bark beetles. Although this method has been shown to be effective, it is not clear whether the effect arises when pre-outbreak populations are small or during the epidemic phase when outbreaks are growing. We adopted a population dynamics approach to determine if the effect of limit or basal area thinning could be observed in the form of differential beetle recruitment using lodgepole pine ( Pinus contorta Dougl. ex Loud.) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) mortality data from previously published studies as a proxy measure of mountain pine beetle ( Dendroctonus ponderosae Hopkins) population size. We found that mountain pine beetle populations exhibit density-dependent population dynamics that are influenced by the silvicultural history of their host’s stand. Thinning did not change the epidemic equilibrium but instead caused a shift in dynamics from linear to nonlinear. In a validation test, the models developed for thinned and unthinned stands predicted reproductive rates in independent locations. These data also suggest the epidemic dynamics of mountain pine beetle may be sensitive to perturbations and to systematic trends associated with climate variability and climate change.


2021 ◽  
Vol 9 (8) ◽  
pp. 1641
Author(s):  
Javier E. Mercado ◽  
Beatriz Ortiz-Santana ◽  
Shannon L. Kay

Fungal and mite associates may drive changes in bark beetle populations, and mechanisms constraining beetle irruptions may be hidden in endemic populations. We characterized common fungi of endemic-level Jeffrey pine beetle (JPB) in western USA and analyzed their dissemination by JPB (maxillae and fecal pellet) and fungivorous mites to identify if endogenous regulation drove the population. We hypothesized that: (1) as in near-endemic mountain pine beetle populations, JPB’s mutualistic fungus would either be less abundant in endemic than in non-endemic populations or that another fungus may be more prevalent; (2) JPB primarily transports its mutualistic fungus, while its fungivorous mites primarily transport another fungus, and (3) based on the prevalence of yeasts in bark beetle symbioses, that a mutualistic interaction with blue-stain fungi present in that system may exist. Grosmannia clavigera was the most frequent JPB symbiont; however, the new here reported antagonist, Ophiostoma minus, was second in frequency. As hypothesized, JPB mostly carried its mutualist fungus while another fungus (i.e., antagonistic) was mainly carried by mites, but no fungal transport was obligate. Furthermore, we found a novel mutualistic interaction between the yeast Kuraishia molischiana and G. clavigera which fostered a growth advantage at temperatures associated with beetle colonization.


2018 ◽  
Vol 10 (1) ◽  
pp. 69 ◽  
Author(s):  
Kyle Mullen ◽  
Fei Yuan ◽  
Martin Mitchell

The recent and intense outbreak (first decade of 2000s) of the mountain pine beetle in the Black Hills of South Dakota and Wyoming, which impacted over 33% of the 1.2 million acre (486,000 ha) Black Hills National Forest, illustrates what can occur when forest management practices intersect with natural climatic oscillations and climate change to create the “perfect storm” in a region where the physical environment sets the stage for a plethora of economic activities ranging from extractive industries to tourism. This study evaluates the potential of WorldView-2 satellite imagery for green-attacked tree detection in the ponderosa pine forest of the Black Hills, USA. It also discusses the consequences of long term fire policy and climate change, and the use of remote sensing technology to enhance mitigation. It was found that the near-infrared one (band 7) of WorldView-2 imagery had the highest influence on the green-attack classification. The Random Forest classification produced the best results when transferred to the independent dataset, whereas the Logistic Regression models consistently yielded the highest accuracies when cross-validated with the training data. Lessons learned include: (1) utilizing recent advances in remote sensing technologies, most notably the use of WorldView-2 data, to assist in more effectively implementing mitigation measures during an epidemic, and (2) implementing pre-emptive thinning strategies; both of which can be applied elsewhere in the American West to more effectively blunt or preclude the consequences of a mountain pine beetle outbreak on an existing ponderosa pine forest. 


1982 ◽  
Author(s):  
William F. McCambridge ◽  
Frank G. Hawksworth ◽  
Carleton B. Edminster ◽  
John G. Laut

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