Susceptibility of lodgepole pine to infestation by mountain pine beetles following partial cutting of stands

1989 ◽  
Vol 19 (2) ◽  
pp. 284-284
Author(s):  
Gene D. Amman ◽  
Mark D. McGregor ◽  
Richard F. Schmitz ◽  
Robert D. Oakes

not available

1989 ◽  
Vol 19 (5) ◽  
pp. 566-574 ◽  
Author(s):  
Richard F. Schmitz ◽  
Mark D. McGregor ◽  
Gene D. Amman ◽  
Robert D. Oakes

Passive barrier traps deployed at three heights above ground were used to determine the effect of five intensities of partial cutting of lodgepole pine (Pinuscontorta Dougl. ex Loud. var. latifolia Engelm.) and two unthinned check stands on response of flying mountain pine beetles (Dendroctonusponderosae Hopkins) from 1980 to 1983 on two sites in western Montana. Percentages of mountain pine beetles caught 4 years after thinning were significantly greater in the least severely thinned (27.6 m2 basal area/ha) treatment (27%) and the unthinned check (28%) than in the 25.4 cm diameter limit (8%) and the 23.0 m2 basal area/ha (7%) thinnings (P < 0.05). Numbers of mountain pine beetles trapped in the 18.4 m2 basal area/ha thinning did not differ significantly from other treatments. The proportions of mountain pine beetles caught at three trapping heights differed significantly (P < 0.05), totaling 63, 28, and 9% at midbole, midcrown, and 1.8 m above ground, respectively. Fewer trees were killed in relation to the numbers of mountain pine beetles trapped in the most severely thinned stands. However, tree mortality rates could not be attributed to thinning-induced changes in tree vigor. These findings, and the preference of flying mountain pine beetles for the midbole stratum, suggest that stand environment is an important factor regulating the severity of tree killing.


1985 ◽  
Vol 117 (3) ◽  
pp. 267-275 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton

AbstractThe relationship between the density of insect holes in the bark (X1) and the density of emerged mountain pine beetles (Y) was investigated in naturally infested lodgepole pine in south-central British Columbia. The density of exit and ventilation holes (Ho) that were present in the bark prior to emergence by mountain pine beetle averaged 10% of all holes present following the emergence period. There was a weak but significant inverse relationship between Ho and both phloem thickness and density of emerged mountain pine beetles. Painting the bark with light-color latex paint did not affect survival or the temporal pattern of emergence by mountain pine beetle but ensured identification and greatly enhanced counting of fresh exit holes. Of the several regression models investigated, the relation between Y and both X1 and X2 (= X1 – Ho) was best fitted by a log-log linear model. A method is suggested for setting limits on the size of exit holes cut by mountain pine beetle in order to exclude from X2 much of the variation caused by exit holes cut by associated insects. A simple mathematical model was developed of the relationship between mean density of exit holes and the density of emerged mountain pine beetles.


1989 ◽  
Vol 19 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Gene D. Amman ◽  
Ralph W. Thier ◽  
Mark D. McGregor ◽  
Richard F. Schmitz

Verbenone, a bark beetle antiaggregative pheromone, was deployed in lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) stands in the Sawtooth National Forest, Idaho, U.S.A., to test its efficacy in reducing tree losses to mountain pine beetle (Dendroctonusponderosae Hopkins). Treatments tested were verbenone, mountain pine beetle tree bait, verbenone plus mountain pine beetle tree bait, and a control. Each treatment was applied individually to 1-ha blocks and replicated four times. Treatment effects were measured by percentage of infested (i.e., mass-attacked) lodgepole pine. ANOVA showed a significant treatment effect (P < 0.005). Blocks treated with mountain pine beetle tree baits had significantly (P < 0.002) higher average percentages of infested trees (24.4%), whereas no significant difference occurred in percentages of infested trees among the other three treatments. Average percentages of infested trees were 0.9% for verbenone, 7.4% for verbenone plus mountain pine beetle tree bait, and 3.3% for the control. A 2.3-fold reduction in infested trees occurred when verbenone was applied to blocks treated with mountain pine beetle tree baits.


2000 ◽  
Vol 132 (6) ◽  
pp. 799-810 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton ◽  
T.L. Shore

AbstractBark beetles were trapped for two summers in a mature stand of lodgepole pine, Pinus contorta var. latifolia Engelmann (Pinaceae), infested by mountain pine beetle, Dendroctonus ponderosae Hopkins, near Princeton, British Columbia. Columns of flight-barrier traps were suspended next to uninfested live trees and from dead brood trees containing new adult beetles. The brood trees had been treated in the previous year with mountain pine beetle pheromone bait alone or in combination with Ips pini Say (Coleoptera: Scolytidae) pheromone bait and subsequently killed by mountain pine beetles. A total of 3376 individuals from 30 species of Scolytidae were captured in the traps. Most of the species for which lodgepole pine is a nonhost or occasional host were captured in low numbers (one or two specimens). The most abundant species (> 30 individuals) were D. ponderosae, I. pini, Hylurgops porosus LeConte, Pityogenes knechteli Swaine, and Trypodendron lineatum Olivier. The treatments affected captures of mountain pine beetles and I. pini but only in the year when trees were either unbaited or baited simultaneously for mountain pine beetle and I. pini. There were significant differences among the five most abundant species in the mean heights and mean Julian dates of capture. In addition to host condition requirements, these differences reflected partitioning of the food and habitat resource and competitive interactions among species. There was no interaction between treatment and trap height, indicating that treatment did not affect the height distribution of flying beetles.


2014 ◽  
Vol 147 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Fraser R. McKee ◽  
Dezene P.W. Huber ◽  
B. Staffan Lindgren ◽  
Robert S. Hodgkinson ◽  
Brian H. Aukema

AbstractThe mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), outbreak in British Columbia and Alberta, Canada, currently extends over 18.3 million ha of pine forest. The principal host of the insect is lodgepole pine, Pinus contorta var. latifolia Englemann (Pineaceae) although it is a generalist herbivore on pines. Mountain pine beetles do not typically colonise spruce. However, during the current outbreak, several instances of mountain pine beetle attack on interior hybrid spruce, Picea glauca (Moench) Voss×Picea engelmannii Parry ex. Engelmann (Pinaceae) have been noted in areas where severe lodgepole pine mortality has occurred. Occasionally, beetle reproduction within spruce has been successful. Reproductive behaviours of mountain pine beetles reared from pine and spruce, such as female host acceptance and male joining behaviour, were studied on bolts of pine and spruce in laboratory bioassays. Females more readily accepted spruce host material relative to pine. Females that developed in spruce had higher rates of host acceptance of both pine and spruce host material than females that had developed in pine. We interpret these latter results with caution, however, as inference is partially restricted by sourcing viable insects from one spruce in this study. Implications of these findings to the concepts of host adaptation and population dynamics of this eruptive herbivore are discussed.


1991 ◽  
Vol 123 (2) ◽  
pp. 299-304 ◽  
Author(s):  
Henry A. Moeck ◽  
Clarence S. Simmons

AbstractThree field tests were conducted in which fresh lodgepole pine (Pinus contorta Douglas var. latifolia Engl.) material, namely bolts with and without bark, bark only, and freshly tapped resin, were placed in beetle-excluding “greenhouse” cages; empty cages served as controls. Two “window” flight traps per cage, at right angles to each other, caught mountain pine beetles (Dendroctonus ponderosae Hopkins) arriving at the cages. Significantly more mountain pine beetles were trapped at cages baited with bolts and wood only than at empty control cages. Primary attraction in the mountain pine beetle is thus established, in the absence of pheromones and normal visual cues (tree stem silhouette). More beetles were trapped at cages baited with bark only and with resin than at empty control cages, but differences were not significant at p = 0.05. The sex ratio of trapped beetles (4.83 females: 1 male) was more than twice as high as the reported sex ratios of free-flying and emerging beetles.


1992 ◽  
Vol 113 (1-5) ◽  
pp. 441-450 ◽  
Author(s):  
L. Safranyik ◽  
D. A. Linton ◽  
R. Silversides ◽  
L. H. McMullen

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