Response of the mountain pine beetle, Dendroctonusponderosae Hopkins (Coleoptera: Scolytidae), to five semiochemicals in British Columbia lodgepole pine forests

1987 ◽  
Vol 17 (2) ◽  
pp. 118-128 ◽  
Author(s):  
J. H. Borden ◽  
L. C. Ryker ◽  
L. J. Chong ◽  
H. D. Pierce Jr. ◽  
B. D. Johnston ◽  
...  

Five principal semiochemicals were field tested in multiple funnel traps for behavioral activity against Dendroctonusponderosae infesting lodgepole pine, Pinuscontorta var. latifolia Engelmann, in British Columbia. The basic experimental design was to test each compound by adding it in varying concentration or enantiomeric composition to a blend of other semiochemicals. (−)-trans-Verbenol was attractive to both sexes. (±)-exo-Brevicomin and (±)-frontalin (in one of two experiments) were attractive with other semiochemicals to females at a release rate of 0.05 mg/24 h. At higher release rates (±)-exo-brevicomin was inhibitory to males, and frontalin was inhibitory to both sexes. Thus both serve as multifunctional pheromones. For neither exo-brevicomin nor frontalin were the separate enantiomers attractive at the low release rate, suggesting that they had an additive effect. However, at the high release rate both enantiomers mimicked the inhibitory effect of the racemates. Verbenone acted as an antiaggregation pheromone for both sexes. Increasing the release rate of myrcene from 18 to 150 mg/24 h to approximate the release rate from a newly attacked tree had the effect of doubling the catch of responding beetles. A conceptual model is proposed for the sequential interaction of these semiochemicals in the mass attack of a tree. Pioneer females release trans-verbenol, which acts in combination with myrcene from the host tree to attract mainly males. The responding males release exo-brevicomin and later frontalin, which in combination with trans-verbenol and myrcene attract mainly females. Meanwhile autoxidation of α-pinene in the host resin results first in the production of predominately trans-verbenol, which supplements that produced by the beetles. Later, autoxidation of α-pinene and microbial conversion of cis- and trans-verbenol result in the production of the antiaggregation pheromone verbenone. This compound, in combination with large amounts of exo-brevicomin and frontalin as the tree becomes fully occupied, results in the close-range redirection of responding beetles toward nearby trees.

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.


1992 ◽  
Vol 22 (4) ◽  
pp. 436-441 ◽  
Author(s):  
Patrick J. Shea ◽  
Mark D. McGregor ◽  
Gary E. Daterman

Mountain pine beetle, Dendroctonusponderosae Hopkins, is the primary pest affecting lodgepole pine, Pinuscontorta var. latifolia Engelm., ecosystems in western North America. In 1988, aerial treatments of the antiaggregation pheromone, verbenone, were applied to lodgepole pine stands infested with mountain pine beetle in northwestern Montana. The pheromone was formulated by PHERO TECH Inc. in controlled-release, cylindrical 5 × 5 mm plastic beads and applied without benefit of a sticker at the rate of 54 g verbenone per hectare. There were significantly fewer successfully attacked trees on the treated plots, as evidenced by (i) a fourfold greater incidence of current-year attacked trees per hectare in the untreated check plots and (ii) the significantly lower (α = 0.05) ratio of 1988:1987 attacked trees in the treated plots. Further, the number of trees per hectare resisting attacks (as reflected by number of trees pitching out bark beetles) was higher (α = 0.05) in the treated plots. More pitch outs occurred in treated plots presumably because avoidance of verbenone by beetles reduced the number of beetles below that needed to overcome the natural resistance of attacked trees.


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.


2005 ◽  
Vol 119 (2) ◽  
pp. 186 ◽  
Author(s):  
Gilbert Proulx ◽  
Rhonda M. Kariz

In central British Columbia, recent epidemics of Mountain Pine Beetle (Dendroctonus ponderosae) have resulted in the use of expansive clearcut areas to remove infested mature and old Lodgepole Pine (Pinus contorta) stands. This study aimed to determine if Moose (Alces alces) use late-successional Lodgepole Pine stands in mid- to late-winter. Moose activity and habitat use was determined during February-March track surveys in 2000 (60 km) and 2001 (55.7 km). In 2000 (69 tracks) and 2001 (313 tracks), Moose track distribution differed significantly (P < 0.05) from random. They were significantly more abundant than predicted in young stands (dominated by Picea spp.), or early seral stages; they were less abundant than predicted in mature and old Lodgepole Pine stands. It is unlikely that harvesting late-successional Lodgepole Pine stands would affect Moose winter habitat supply.


2010 ◽  
Vol 40 (6) ◽  
pp. 1109-1127 ◽  
Author(s):  
Jean L. Heineman ◽  
Donald L. Sachs ◽  
W. Jean Mather ◽  
Suzanne W. Simard

Lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) has been extensively planted throughout interior British Columbia, and as a result may be particularly susceptible to climate-induced changes in the range and severity of common damaging agents. We quantified the presence of 14 damaging agents in sixty-six 15- to 30-year-old pine stands. Hard pine stem rusts, primarily western gall rust, were present on every site. We used logistic regression to predict individual agent presence from climatic, location, site, and treatment factors and calculated odds ratios to evaluate whether risk to lodgepole pine increases or decreases as these factors change. Risk of damage from serious agents (stem disease, root disease, and mountain pine beetle) increased with increasing latitude; however, in several of these models, risk also increased as temperature of the coldest month got warmer. We also found evidence that increasing risk of damage from agents that are currently less serious (sequoia pitch moth, pine needle cast, and pine terminal weevil) was associated with warming and (or) increasingly dry climatic conditions. Given the predominance of lodgepole pine in northerly ecosystems and the prediction that climate change effects will increase with latitude, our results suggest the need to consider potential increases in damage from diseases and insects during silviculture planning and timber supply prediction.


1993 ◽  
Vol 23 (6) ◽  
pp. 1108-1113 ◽  
Author(s):  
J.H. Borden ◽  
L.J. Chong ◽  
B.S. Lindgren ◽  
E.J. Begin ◽  
T.M. Ebata ◽  
...  

Seven, split-block experiments throughout British Columbia in 1989 tested the efficacy of binary tree baits containing the pheromones trans-verbenol and exo-brevicomin or ternary baits with the addition of the host tree kairomone myrcene for containing and concentrating infestations of the mountain pine beetle, Dendroctonusponderosae Hopkins, in stands of lodgepole pine, Pinuscontorta var. latifolia Engelm. Attack densities on baited trees, attack frequencies of baited trees and trees within 10 m of the baited trees, and the ratios of newly attacked, green, trees to previously attacked, red, trees were generally statistically equal between sub-blocks containing binary or ternary baits. Where statistically significant differences occurred for one or more of the above criteria in one experiment, they were generally offset by statistically significant differences in the opposite direction in another experiment. Two individual-tree experiments in 1990 that supported the equality of binary and ternary baits indicated that raising the release rate of trans-verbenol in binary baits tended to reduce their efficacy (possibly because of contamination with the antiaggregation pheromone verbenone) and showed that increasing the release rate of exo-brevicomin tended to counteract this effect. When attack frequencies were subdivided by diameter class of available trees attacked, all baits were effective in inducing attack on available trees <30.0 cm diameter at breast height (1.3 m), but attack on baited and control trees ≥30 cm diameter at breast height was equal. Provided that the trans-verbenol in binary baits does not contain or autoxidize to verbenone, myrcene can be deleted from operational tree baits.


2015 ◽  
Vol 45 (10) ◽  
pp. 1387-1396 ◽  
Author(s):  
René I. Alfaro ◽  
Lara van Akker ◽  
Brad Hawkes

The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera, Curculionidae), a native insect of North America, periodically reaches population sizes that cause serious economic impact to the forest industry in western North America. The most recent outbreak in British Columbia (BC), Canada, which began in the late 1990s, is only now (2015) abating, after causing unprecedented tree mortality in lodgepole pine (Pinus contorta Douglas ex. Loudon) forests. In this paper, we make use of permanent research plots to report on the condition of lodgepole pine forests in the Chilcotin Plateau of central BC, which underwent two fully documented mountain pine beetle outbreaks. In this region, the first outbreak started in the late 1970s and lasted until the mid-1980s; the second outbreak began in the early 2000s and ended in 2010. We measured the impacts of these outbreaks in terms of tree mortality and describe the characteristics of the legacies that remain following these outbreaks, including survivors in various canopy layers and levels of existing and new regeneration. We provide evidence in support of the existence of postdisturbance legacies that classify into five distinct stand structure types. Abundant regeneration and surviving intermediate canopy layers in most stands indicate that management actions to restock pine stands in this area will not likely be necessary. The information provided by this study is important for estimating future forest development and timber supply and for forest planning and management.


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