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John H. Borden - One of the best experts on this subject based on the ideXlab platform.
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Comparative Behavioural Responses of Dryocoetes confusus Swaine, Dendroctonus rufipennis (Kirby), and Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae) to Angiosperm Tree Bark Volatiles
Environmental Entomology, 2003Co-Authors: Dezene P. W. Huber, John H. BordenAbstract:Abstract Synthetic, angiosperm bark-derived volatiles, which elicit antennal responses in a number of coniferophagous bark beetles (Coleoptera: Scolytidae), were tested in groups for their ability to disrupt the pheromone-positive response of the spruce beetle (SB), Dendroctonus rufipennis (Kirby), the western balsam bark beetle (WBBB), Dryocoetes confusus Swaine, and the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, to attractant-baited traps. One complex mixture disrupted WBBB response to pheromone-baited multiple-funnel traps to a level not significantly different than that in unbaited control traps. No group of compounds, including a group of green leaf volatiles, was active in disrupting SB response, a result that contrasts other published findings and that is different from the behavioral responses that are elicited by nonhost volatiles in other species of coniferophagous bark beetles. For the MPB, the two green leaf alcohols, 1-hexanol and (Z)-3-hexen-1-ol, were highly disruptive. In...
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Co-baiting for spruce beetles, Dendroctonus rufipennis, and western balsam bark beetles, Dryocoetes confusus (Coleoptera: Scolytidae)
Canadian Journal of Forest Research, 2000Co-Authors: Matthew E Greenwood, John H. BordenAbstract:Co-baiting to contain and concentrate the spruce beetle, Dendroctonus rufipennis (Kirby), and the western balsam bark beetle, Dryocoetes confusus Swaine, was investigated at four locations in British Columbia. Two 9-ha areas were established at each location; one was baited and the other left as a control. Single "interior firs," Abies bifolia A. Murray × Abies lasiocarpa (Hook.) Nutt., or groups of two or three trees, were baited with (±)-exo-brevicomin released at 1.0 mg/24 h. "Interior spruces," Picea engelmannii Engelm. ex Parry × Picea glauca (Moench) Voss, were baited with frontalin released at 0.1, 0.6, or 2.5 mg/24 h, or at 0.6 mg/24 h with alpha-pinene, ethanol, or ethyl crotonate. Another experiment investigated possible interspecific interference between D. confusus and D. rufipennis baits. Ratios of currently attacked "green" trees to previously attacked "red" trees for both insects were significantly higher in baited than in control areas, indicating that populations were contained. Baiting, however, did not attract either insect from a zone surrounding each baited area. There was a significant increase in D. confusus attack when two trees instead of one were baited per centre, no increase in D. rufipennis attack when frontalin was released alone or with the potential adjuvants, no effect of frontalin release rates on the percentage of trees attacked by D. rufipennis, and no indication of cross-repellency between baits.
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DIFFERENTIAL BIOACTIVITY OF CONOPHTHORIN ON FOUR SPECIES OF NORTH AMERICAN BARK BEETLES (COLEOPTERA: SCOLYTIDAE)
The Canadian Entomologist, 2000Co-Authors: Dezene P. W. Huber, John H. Borden, Nicole L. Jeans-williams, Regine GriesAbstract:La conophtorine, une substance volatile de l'ecorce des angiospermes, a ete testee a des taux d'emission de 3,0 et de 0,3 mg/24 h chez quatre especes de scolytes, le Dendroctone du Douglas, Dendroctonus pseudotsugae Hopkins, le Dendroctone de l'epinette, Dendroctonus rufipennis (Kirby), le Scolyte du pin, Ips pini (Say) et le Scolyte du sapin de l'ouest, Dryocoetes confusus Swaine. Les reactions de D. pseudotsugae et d'I. pini (au cours de l'une de deux experiences) et des femelles de D. confusus a des pieges garnis d'une substance attirante ont ete perturbees par la conophthorine et cela en fonction de la dose. Dendroctonus rufipennis ne reagit pas a la conophthorine. Nos resultats demontrent que l'effet repoussant de la conophthorine agit aussi sur Ips DeGeer et confirment les resultats d'experiences anterieures sur D. pseudotsugae. La conophthorine peut s'averer utile pour proteger le bois coupe des invasions de scolytes.
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Co-baiting for spruce beetles, Dendroctonus rufipennis, and western balsam bark beetles, Dryocoetes confusus (Coleoptera: Scolytidae)
Canadian Journal of Forest Research, 2000Co-Authors: Matthew E Greenwood, John H. BordenAbstract:Co-baiting to contain and concentrate the spruce beetle, Dendroctonus rufipennis (Kirby), and the western balsam bark beetle, Dryocoetes confusus Swaine, was investigated at four locations in British Columbia. Two 9-ha areas were established at each location; one was baited and the other left as a control. Single "interior firs," Abies bifolia A. Murray × Abies lasiocarpa (Hook.) Nutt., or groups of two or three trees, were baited with (±)-exo-brevicomin released at 1.0 mg/24 h. "Interior spruces," Picea engelmannii Engelm. ex Parry × Picea glauca (Moench) Voss, were baited with frontalin released at 0.1, 0.6, or 2.5 mg/24 h, or at 0.6 mg/24 h with alpha-pinene, ethanol, or ethyl crotonate. Another experiment investigated possible interspecific interference between D. confusus and D. rufipennis baits. Ratios of currently attacked "green" trees to previously attacked "red" trees for both insects were significantly higher in baited than in control areas, indicating that populations were contained. Baiting, ...
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Bioactivity and efficacy of MCOL and seudenol as potential attractive bait components for Dendroctonus rufipennis (Coleoptera : Scolytidae)
The Canadian Entomologist, 1999Co-Authors: Robert R. Setter, John H. BordenAbstract:AbstractIn randomized complete block experiments using multiple-funnel traps frontalin was only moderately attractive to spruce beetles, Dendroctonus rufipennis Kirby, in northern British Columbia. MCOL (1-methylcyclohex-2-en-1-ol) of any enantiomeric composition significantly enhanced the attraction of both sexes (up to 3.4 and 4.2 times for females and males, respectively) to traps baited with frontalin. The lack of an enantiospecific preference for MCOL aligns beetles in northern British Columbia with those in southeastern British Columbia and northern Alberta, but not with enantiospecific populations in southern British Columbia and Alaska. In tree baits, neither MCOL nor seudenol (3-methylcyclohex-2-en-1-ol) enhanced the efficacy of frontalin. The power of frontalin alone at a release rate of 1.2 mg per 24 h (half the rate in commercial baits) indicates that the currently used operational tree baits could be modified by lowering the dose and eliminating α-pinene.
Therese M. Poland - One of the best experts on this subject based on the ideXlab platform.
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Semiochemical-Induced Competition Between Dendroctonus rufipennis and Two Secondary Species, Ips tridens and Dryocoetes affaber (Coleoptera: Scolytidae)
Journal of Economic Entomology, 1998Co-Authors: Therese M. Poland, John H. BordenAbstract:We investigated the hypothesis that interspecific interactions between the spruce beetle, Dendroctonus rufipennis Kirby, and 2 secondary species, Ips tridens Mannerheim and Dryocoetes affaber Mannerheim, adversely affect species beetle progeny production and survival. In field experiments in the British Columbia interior, attack by the secondary species was induced by placing pheromone baits on felled trees just after spruce beetle attack. Spruce beetle attack densities, gallery length per square meter, and progeny densities were significantly reduced in trees that were baited with D. affaber pheromones or D. affaber and I. tridens pheromones. Resource exploitation and synomonal interference with subsequent spruce beetle attacks were the primary competitive mechanisms. No evidence for direct interference was found. Because the impact of the secondary species was not pronounced, semiochemical-induced competitive displacement of the spruce beetle after it has established would not be practical for retarding the development of, or suppressing, beetle outbreaks.
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Competitive Exclusion of Dendroctonus rufipennis Induced by Pheromones of Ips tridens and Dryocoetes affaber (Coleoptera: Scolytidae)
Journal of Economic Entomology, 1998Co-Authors: Therese M. Poland, John H. BordenAbstract:We tested the feasibility of competitive exclusion as a potential management tactic for the spruce beetle, Dendroctonus rufipennis Kirby, using pre-attack baiting with pheromones of 2 secondary species, Ips tridens Mannerheim and Dryocoetes affaber Mannerheim. Spruce beetle attack densities, gallery lengths per square meter, and progeny densities were significantly reduced by up to 78% in individual felled trees baited with the I. tridens pheromones (+/-)-ipsdienol and (-)-cis-verbernol, and the D. affaber pheromones (+/-)-exo-and (+)-endo-brevicomin, or pheromones of both secondary species. A simplified D. affaber bait consisting of only (+/-)-endo-brevicomin also significantly reduced spruce beetle attacks, resource exploitation, and progeny production. Baiting with I. tridens pheromones also reduced spruce beetle attack and success in simulated patches of windthrown trees. Resource exploitation and indirect interference by synomonal inhibition of spruce beetle attack are the most likely competitive mechanisms invoked. Competitive exclusion of the spruce beetle may provide an alternative management tactic where traditional methods based on tree removal, widespread harvesting, and the use of insecticides are not feasible.
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green leaf volatiles disrupt responses by the spruce beetle Dendroctonus rufipennis and the western pine beetle Dendroctonus brevicomis coleoptera scolytidae to attractant baited traps
Journal of the Entomological Society of British Columbia, 1998Co-Authors: Therese M. Poland, A.j. Stock, John H. Borden, L.j. ChongAbstract:We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of spruce beetles, Dendroctonus rufipennis Kirby, and western pine beetles, Dendroctonus brevicomis LeConte, to attraetant-baited traps. Two green leaf aldehydes, hexanal and (E)-2-hexenal, reduced the number of spruce beetles captured to intermediate levels and one green leaf alcohol, hexanol, significantly reduced spruce beetle trap catches. Together, the green leaf alcohols and aldehydes reduced trap catches by 78.7 and 89.3% for males and females, respectively. The green leaf aldehyde, (E)-2-hexenal, and two green leaf alcohols, (E)-2-hexen-l-ol and (Z)-2-hexen-l-ol, significantly reduced the numbers of male western pine beetles captured and the latter compound also reduced the numbers of female western pine beetles captured. The greatest disruptive effect for the western pine beetle was 46.7% for (Z)-2-hexen-l-ol on males. These results support the hypothesis that GLVs common to non-host angiosperms are disruptive to pheromone and kairomone attraction of conifer-attacking bark beetles. While general GLVs are disruptive to several scolytid species, the most disruptive individual GLV components and blends differ by scolytid species and may reflect differences in the volatile characteristics of their particular ecosystems.
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green leaf volatiles disrupt responses by the spruce beetle Dendroctonus rufipennis and the western pine beetle Dendroctonus brevicomis coleoptera scolytidae to attractant baited traps
Journal of the Entomological Society of British Columbia, 1998Co-Authors: Therese M. Poland, A.j. Stock, J. H. Borden, L.j. ChongAbstract:We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of spruce beetles, Dendroctonus rufipennis Kirby, and western pine beetles, Dendroctonus brevicomis LeConte, to attraetant-baited traps. Two green leaf aldehydes, hexanal and (E)-2-hexenal, reduced the number of spruce beetles captured to intermediate levels and one green leaf alcohol, hexanol, significantly reduced spruce beetle trap catches. Together, the green leaf alcohols and aldehydes reduced trap catches by 78.7 and 89.3% for males and females, respectively. The green leaf aldehyde, (E)-2-hexenal, and two green leaf alcohols, (E)-2-hexen-l-ol and (Z)-2-hexen-l-ol, significantly reduced the numbers of male western pine beetles captured and the latter compound also reduced the numbers of female western pine beetles captured. The greatest disruptive effect for the western pine beetle was 46.7% for (Z)-2-hexen-l-ol on males. These results support the hypothesis that GLVs common to non-host angiosperms are disruptive to pheromone and kairomone attraction of conifer-attacking bark beetles. While general GLVs are disruptive to several scolytid species, the most disruptive individual GLV components and blends differ by scolytid species and may reflect differences in the volatile characteristics of their particular ecosystems.
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Attraction of a bark beetle predator, Thanasimus undatulus (Coleoptera: Cleridae), to pheromones of the spruce beetle and two secondary bark beetles (Coleoptera: Scolytidae)
Journal of the Entomological Society of British Columbia, 1997Co-Authors: Therese M. Poland, John H. BordenAbstract:The bark beetle predator Thanasimus undatulus Say was captured in statistically significant numbers (total catch = 470, 713, and 137) in three field experiments using multiple-funnel traps baited with various combinations of pheromones for the spruce beetle, Dendroctonus rufipennis Kirby, and the secondary bark beetles Dryocoetes affaber Mannerheim, and Ips tridens Mannerheim. Thanasimus undatulus was attracted to frontalin and a-pinene, the commercial spruce beetle lure, alone or combined with the D. affaber pheromones (+)-endo- and (±)-exo-brevicomin. Ips tridens pheromones, (±)- and (+)-ipsdienol, significantly increased the numbers of T. undatulus attracted to spruce beetle lures. Additional I. tridens pheromone components, (-)-cis-verbenol and amitinol, did not increase attraction to spruce beetle lures with added (±)-ipsdienol. Attraction to I. tridens pheromones indicates that baiting susceptible hosts with I. tridens pheromones to induce competitive exclusion of the spruce beetle may also lead to increased densities of the natural enemy, T. undatulus . Key words: Thanasimus undatulus ; Dendroctonus rufipennis ; Ips tridens ; Dryocoetes affaber ; ipsdienol; kairomone; predator; Princeton; British Columbia
J. H. Borden - One of the best experts on this subject based on the ideXlab platform.
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Dendroctonus brevicomis (Coleoptera: Scolytidae) to
2015Co-Authors: T. M. Poland, A.j. Stock, J. H. Borden, L.j. ChongAbstract:- Green leaf volatiles disrupt responses by the spruce beetle, Dendroctonus rufipennis, and the western pine beetle
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green leaf volatiles disrupt responses by the spruce beetle Dendroctonus rufipennis and the western pine beetle Dendroctonus brevicomis coleoptera scolytidae to attractant baited traps
Journal of the Entomological Society of British Columbia, 1998Co-Authors: Therese M. Poland, A.j. Stock, J. H. Borden, L.j. ChongAbstract:We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of spruce beetles, Dendroctonus rufipennis Kirby, and western pine beetles, Dendroctonus brevicomis LeConte, to attraetant-baited traps. Two green leaf aldehydes, hexanal and (E)-2-hexenal, reduced the number of spruce beetles captured to intermediate levels and one green leaf alcohol, hexanol, significantly reduced spruce beetle trap catches. Together, the green leaf alcohols and aldehydes reduced trap catches by 78.7 and 89.3% for males and females, respectively. The green leaf aldehyde, (E)-2-hexenal, and two green leaf alcohols, (E)-2-hexen-l-ol and (Z)-2-hexen-l-ol, significantly reduced the numbers of male western pine beetles captured and the latter compound also reduced the numbers of female western pine beetles captured. The greatest disruptive effect for the western pine beetle was 46.7% for (Z)-2-hexen-l-ol on males. These results support the hypothesis that GLVs common to non-host angiosperms are disruptive to pheromone and kairomone attraction of conifer-attacking bark beetles. While general GLVs are disruptive to several scolytid species, the most disruptive individual GLV components and blends differ by scolytid species and may reflect differences in the volatile characteristics of their particular ecosystems.
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Disruption of Secondary Attraction of the Spruce Beetle, Dendroctonus rufipennis, by Pheromones of Two Sympatric Species
Journal of Chemical Ecology, 1998Co-Authors: T. M. Poland, J. H. BordenAbstract:Capture of spruce beetles, Dendroctonus rufipennis , in multiple-funnel traps baited with frontalin and α-pinene was reduced by up to 42% in the presence of synthetic (+)- exo - and (+)- endo -brevicomin, aggregation pheromones of the sympatric species Dryocoeles affaber . (±)- endo -Brevicomin was inhibitory to spruce beetles in two experiments and (±)- exo -brevicomin was inhibitory in one experiment, reducing spruce beetle trap catches by up to 87% and 75%, respectively. Spruce beetle trap catches were also reduced by 85% by (±)- or (+)-ipsdienol, but not by (−)-ipsdienol. Ips tridens , a second sympatric species, produces both enantiomers of ipsdienol in its pheromone blend. Responses by D. affaber to its own pheromone were significantly enhanced by addition of the spruce beetle lure. Enantiospecific pheromones of secondary competing species, or less costly racemic substitutes, may be useful for managing spruce beetles using competitive displacement or exclusion. Baiting susceptible hosts with pheromones of secondary species may enhance attack by secondary species, while partially repelling spruce beetles.
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Regionally-specific bioactivity of two new pheromones for Dendroctonus rufipennis (Kirby) (Col., Scolytidae)
Journal of Applied Entomology, 1996Co-Authors: J. H. Borden, L.j. Chong, R. A. Werner, E. H. Holsten, Gerhard Gries, H. Wieser, E. A. Dixon, H. F. CerezkeAbstract:Abstract: 1-Methyl-2-cyclohexen-1-ol (MCOL) was shown for the first time to occur in the frass produced by female spruce beetles, Dendroctonus rufipennis (Kirby). MCOL and 4-methylene-6,6-dimethylbicyclo[3.1.1]hept-2-ene (verbenene) were evaluated in five geographic locations for attractiveness to spruce beetles. In trapping experiments (±)- or (+)- MCOL enhanced attraction to a standard blend of α-pinene with frontalin in two Alaska locations. (+)-MCOL was attractive and (-)-MCOL inhibitory in south-central British Columbia, and (+)-, (-)- and (±)-MCOL were all weakly attractive in one of three experiments in southeastern British Columbia and northern Alberta. Verbenene was attractive only in combination with the standard blend plus MCOL in Alaska. In comparison with the standard bait, tree baits incorporating (±)- or (+)-MCOL caused higher numbers of trees to be attacked in the interior Alaska locations and (+)- MCOL had the same effect in south-central British Columbia. Density of attack on attacked trees was unaffected. (±)- or (+)-MCOL could improve the operational efficacy of tree baits in Alaska, and (+)-MCOL could be used in south-central British Columbia. Our results indicate that for wide-ranging scolytid species, operational evaluation of new semiochemicals should be regionally specific.
T. M. Poland - One of the best experts on this subject based on the ideXlab platform.
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Dendroctonus brevicomis (Coleoptera: Scolytidae) to
2015Co-Authors: T. M. Poland, A.j. Stock, J. H. Borden, L.j. ChongAbstract:- Green leaf volatiles disrupt responses by the spruce beetle, Dendroctonus rufipennis, and the western pine beetle
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Disruption of Secondary Attraction of the Spruce Beetle, Dendroctonus rufipennis, by Pheromones of Two Sympatric Species
Journal of Chemical Ecology, 1998Co-Authors: T. M. Poland, J. H. BordenAbstract:Capture of spruce beetles, Dendroctonus rufipennis , in multiple-funnel traps baited with frontalin and α-pinene was reduced by up to 42% in the presence of synthetic (+)- exo - and (+)- endo -brevicomin, aggregation pheromones of the sympatric species Dryocoeles affaber . (±)- endo -Brevicomin was inhibitory to spruce beetles in two experiments and (±)- exo -brevicomin was inhibitory in one experiment, reducing spruce beetle trap catches by up to 87% and 75%, respectively. Spruce beetle trap catches were also reduced by 85% by (±)- or (+)-ipsdienol, but not by (−)-ipsdienol. Ips tridens , a second sympatric species, produces both enantiomers of ipsdienol in its pheromone blend. Responses by D. affaber to its own pheromone were significantly enhanced by addition of the spruce beetle lure. Enantiospecific pheromones of secondary competing species, or less costly racemic substitutes, may be useful for managing spruce beetles using competitive displacement or exclusion. Baiting susceptible hosts with pheromones of secondary species may enhance attack by secondary species, while partially repelling spruce beetles.
L.j. Chong - One of the best experts on this subject based on the ideXlab platform.
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Dendroctonus brevicomis (Coleoptera: Scolytidae) to
2015Co-Authors: T. M. Poland, A.j. Stock, J. H. Borden, L.j. ChongAbstract:- Green leaf volatiles disrupt responses by the spruce beetle, Dendroctonus rufipennis, and the western pine beetle
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green leaf volatiles disrupt responses by the spruce beetle Dendroctonus rufipennis and the western pine beetle Dendroctonus brevicomis coleoptera scolytidae to attractant baited traps
Journal of the Entomological Society of British Columbia, 1998Co-Authors: Therese M. Poland, A.j. Stock, John H. Borden, L.j. ChongAbstract:We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of spruce beetles, Dendroctonus rufipennis Kirby, and western pine beetles, Dendroctonus brevicomis LeConte, to attraetant-baited traps. Two green leaf aldehydes, hexanal and (E)-2-hexenal, reduced the number of spruce beetles captured to intermediate levels and one green leaf alcohol, hexanol, significantly reduced spruce beetle trap catches. Together, the green leaf alcohols and aldehydes reduced trap catches by 78.7 and 89.3% for males and females, respectively. The green leaf aldehyde, (E)-2-hexenal, and two green leaf alcohols, (E)-2-hexen-l-ol and (Z)-2-hexen-l-ol, significantly reduced the numbers of male western pine beetles captured and the latter compound also reduced the numbers of female western pine beetles captured. The greatest disruptive effect for the western pine beetle was 46.7% for (Z)-2-hexen-l-ol on males. These results support the hypothesis that GLVs common to non-host angiosperms are disruptive to pheromone and kairomone attraction of conifer-attacking bark beetles. While general GLVs are disruptive to several scolytid species, the most disruptive individual GLV components and blends differ by scolytid species and may reflect differences in the volatile characteristics of their particular ecosystems.
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green leaf volatiles disrupt responses by the spruce beetle Dendroctonus rufipennis and the western pine beetle Dendroctonus brevicomis coleoptera scolytidae to attractant baited traps
Journal of the Entomological Society of British Columbia, 1998Co-Authors: Therese M. Poland, A.j. Stock, J. H. Borden, L.j. ChongAbstract:We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of spruce beetles, Dendroctonus rufipennis Kirby, and western pine beetles, Dendroctonus brevicomis LeConte, to attraetant-baited traps. Two green leaf aldehydes, hexanal and (E)-2-hexenal, reduced the number of spruce beetles captured to intermediate levels and one green leaf alcohol, hexanol, significantly reduced spruce beetle trap catches. Together, the green leaf alcohols and aldehydes reduced trap catches by 78.7 and 89.3% for males and females, respectively. The green leaf aldehyde, (E)-2-hexenal, and two green leaf alcohols, (E)-2-hexen-l-ol and (Z)-2-hexen-l-ol, significantly reduced the numbers of male western pine beetles captured and the latter compound also reduced the numbers of female western pine beetles captured. The greatest disruptive effect for the western pine beetle was 46.7% for (Z)-2-hexen-l-ol on males. These results support the hypothesis that GLVs common to non-host angiosperms are disruptive to pheromone and kairomone attraction of conifer-attacking bark beetles. While general GLVs are disruptive to several scolytid species, the most disruptive individual GLV components and blends differ by scolytid species and may reflect differences in the volatile characteristics of their particular ecosystems.
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Regionally-specific bioactivity of two new pheromones for Dendroctonus rufipennis (Kirby) (Col., Scolytidae)
Journal of Applied Entomology, 1996Co-Authors: J. H. Borden, L.j. Chong, R. A. Werner, E. H. Holsten, Gerhard Gries, H. Wieser, E. A. Dixon, H. F. CerezkeAbstract:Abstract: 1-Methyl-2-cyclohexen-1-ol (MCOL) was shown for the first time to occur in the frass produced by female spruce beetles, Dendroctonus rufipennis (Kirby). MCOL and 4-methylene-6,6-dimethylbicyclo[3.1.1]hept-2-ene (verbenene) were evaluated in five geographic locations for attractiveness to spruce beetles. In trapping experiments (±)- or (+)- MCOL enhanced attraction to a standard blend of α-pinene with frontalin in two Alaska locations. (+)-MCOL was attractive and (-)-MCOL inhibitory in south-central British Columbia, and (+)-, (-)- and (±)-MCOL were all weakly attractive in one of three experiments in southeastern British Columbia and northern Alberta. Verbenene was attractive only in combination with the standard blend plus MCOL in Alaska. In comparison with the standard bait, tree baits incorporating (±)- or (+)-MCOL caused higher numbers of trees to be attacked in the interior Alaska locations and (+)- MCOL had the same effect in south-central British Columbia. Density of attack on attacked trees was unaffected. (±)- or (+)-MCOL could improve the operational efficacy of tree baits in Alaska, and (+)-MCOL could be used in south-central British Columbia. Our results indicate that for wide-ranging scolytid species, operational evaluation of new semiochemicals should be regionally specific.