scholarly journals Spatial associations between infestations of mountain pine beetle and landscape features in the Peace River Region of British Columbia.

2010 ◽  
Author(s):  
Honey-Marie C. de la Giroday
2019 ◽  
Vol 49 (11) ◽  
pp. 1339-1348 ◽  
Author(s):  
Julian Wittische ◽  
Jasmine K. Janes ◽  
Patrick M.A. James

The current mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins, 1902) outbreak has reached more than 25 million hectares of forests in North America, affecting pine species throughout the region and substantially changing landscapes. However, landscape features that enhance or limit dispersal during the geographic expansion associated with the outbreak are poorly understood. One of the obstacles in evaluating the effects of landscape features on dispersal is the parameterization of resistance surfaces, which are often constructed based on biased expert opinion or by making assumptions in the calculation of ecological distances. In this study, we assessed the impact of four environmental variables on MPB genetic connectivity across western Canada. We optimized resistance surfaces using genetic algorithms and models of maximum likelihood population effects, based on pairwise genetic distances and ecological distances calculated using random-walk commute-time distances. Unlike other methods for the development of resistance surfaces, this approach does not make a priori assumptions about the direction or shape of the relationships between environmental features and their cost to movement. We found highest support for a composite resistance surface including elevation and climate. These results further the understanding of MPB movement during an outbreak. Additionally, we demonstrated how to use our results for management purposes.


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.


1989 ◽  
Vol 19 (1) ◽  
pp. 65-68 ◽  
Author(s):  
B. S. Lindgren ◽  
J. H. Borden ◽  
G. H. Cushon ◽  
L. J. Chong ◽  
C. J. Higgins

The effect of the aggregation-inhibiting pheromone verbenone on mountain pine beetle attacks in lodgepole pine stands was assessed by affixing verbenone release devices on trees on a 10 × 10 m grid. In one experiment, aggregation to trees baited with an attractive combination of trans-verbenol, exo-brevicomin, and myrcene was reduced in verbenone-treated blocks compared with control blocks (attractive baits only). The mean number of trees with mass attacks (≥31.3 attacks/m2), mean percentage of available trees mass attacked, and mean total number of trees infested were reduced by 74.3, 66.7, and 58.5%, respectively. The ratio of 1987 attacks to 1986 attacks was reduced from 14.0 to 2.6. In a second experiment, using no attractive baits, verbenone caused similar but nonsignificant reductions. The mean number of trees with mass attacks, mean percentage of available trees mass attacked, and mean total number of trees infested were reduced by 75.2, 53.5, and 62.1%, respectively. The 1987 to 1986 attack ratio was reduced from 13.2 in control blocks to 0.2 in the verbenone-treated blocks, and the percentage of trees that were infested but not mass attacked was significantly increased, from 45.7% in the control blocks to 63.2% in the verbenone-treated blocks. We conclude that verbenone shows promise as a management tool for controlling the mountain pine beetle.


2000 ◽  
Vol 30 (7) ◽  
pp. 1051-1059 ◽  
Author(s):  
Elizabeth M Campbell ◽  
Joseph A Antos

A major decline in the abundance of whitebark pine (Pinus albicaulis Engelm.) has recently occurred in the United States, primarily as a result of white pine blister rust (Cronartium ribicola J.C. Fisch. ex Raben.). However, no information on the status of whitebark pine in British Columbia, Canada, was available. We sampled 54 subalpine stands in British Columbia, examining all whitebark pine trees within plots for evidence of blister rust and mountain pine beetle (Dendroctonus ponderosae Hopk.) damage. About 21% of all whitebark pine stems were dead, and blister rust was the most important agent of mortality. Of all living trees sampled, 27% had obvious blister rust infection (cankers), but actual incidence was suspected of being as high as 44% (using all evidence of blister rust). Blister rust incidence and whitebark pine mortality were significantly related to differences in stand structure and the presence of Ribes spp., but relationships with local climate and site variables were absent or weak. The lack of strong relationships with climate suggests favourable conditions for the spread of the disease throughout most of British Columbia. Very little evidence of mountain pine beetle was found. Overall, the prospects for whitebark pine in British Columbia do not appear good; a large reduction in population levels seems imminent.


1983 ◽  
Vol 13 (2) ◽  
pp. 325-333 ◽  
Author(s):  
J. H. Borden ◽  
J. E. Conn ◽  
L. M. Friskie ◽  
B. E. Scott ◽  
L. J. Chong ◽  
...  

Lodgepole pines, Pinuscontorta var. latifolia Engelm., in three interior British Columbia locations were baited with six monoterpenes alone or combined, and various combinations of the beetle-produced volatiles trans-verbenol, exo-brevicomin, and 3-caren-10-ol. Trees baited with trans-verbenol, exo brevicomin, and the monoterpene 3-carene sustained higher attack densities by the mountain pine beetle, Dendroctonusponderosae Hopkins, and were surrounded by more attacked trees than trees baited with trans-verbenol and 3-carene or unbaited controls. Myrcene was apparently the best of six monoterpenes as a synergist for trans-verbenol. 3-Caren-10-ol appeared to have some activity in an early test but did not prove to be an attractive pheromone in extensive studies. In a 17-ha portion of an infestation, treatment of 99 trees with 3-carene and trans-verbenol apparently caused a higher attack rate, resulting in 56.4% of the available green trees being attacked, as opposed to 22.3% of the available trees in the 14-ha unbaited area. These data as well as the high attack rates associated with trees which also had an exo-brevicomin bait suggest that semiochemicals could be used to contain D. ponderosae infestations and to attract beetles to lethal trap trees.


Sign in / Sign up

Export Citation Format

Share Document