PHYSIOLOGICAL ASPECTS OF LODGEPOLE PINE WOUND RESPONSES TO A FUNGAL SYMBIONT OF THE MOUNTAIN PINE BEETLE, DENDROCTONUS PONDEROSAE (COLEOPTERA: SCOLYTIDAE)

1983 ◽  
Vol 115 (7) ◽  
pp. 723-734 ◽  
Author(s):  
K. F. Raffa ◽  
A. A. Berryman

AbstractThe acetone-soluble fraction of phloem tissue samples from 78 lodgepole pines was examined prior to and following artificial inoculation with Europhium clavigerum, a fungus transmitted by the mountain pine beetle. All trees showed quantitative increases in the concentration of extractives within 3 days after treatment. Further increases continued for at least 7 days. By this time qualitative changes in the chemical composition of the host tissue had also occurred.Trees were defined as resistant or susceptible depending on whether they survived beetle attack under natural conditions. The composition of the acetone-soluble extracts was similar for the constitutive tissue of resistant and susceptible trees, but the total quantity of acetone extractives of reaction tissue was higher in resistant trees.The ability of trees to respond to fungal inoculation is diminished by mass attack. Trees responded more extensively to inoculation prior to, than during, aggregation under field conditions. An experiment was conducted to simulate this relationship under controlled conditions by examining the effect of multiple fungal inoculations on the production of monoterpenes during the wound response. Individual trees showed a weaker quantitative response on stem sections administered high inoculation densities than on stem sections administered only a single inoculation. Those trees which responded most extensively to a single invasion by the pathogen were more responsive at all inoculum densities.

1990 ◽  
Vol 122 (5) ◽  
pp. 769-777 ◽  
Author(s):  
J.H. Borden ◽  
L.J. Chong ◽  
B.S. Lindgren

AbstractBaited tree experiments confirmed the hypothesis that frontalin is a multifunctional pheromone that can induce the mountain pine beetle, Dendroctonus ponderosae Hopkins, to aggregate on and mass-attack lodgepole pine, Pinus conforta var. latifolia Engelmann. A re-examination was undertaken of the role of four known semiochemicals, myrcene, trans-verbenol, exo-brevicomin, and frontalin, tested as tree baits alone (with the exception of myrcene) and in all possible combinations. There was considerable redundancy evident in the semiochemical signal. For example, myrcene + frontalin and trans-verbenol + exo-brevicomin induced attack on baited trees at similar levels of intensity. The results suggest that beetles of either sex could initiate a mass attack. During the most attractive phase of host colonization, redundancy in the semiochemical signal could act as a fail-safe mechanism to ensure perception of and response to odors from an attacked tree. In addition the standard, commercial, tree bait containing myrcene, trans-verbenol, and exo-brevicomin might be modified by deleting myrcene, making a more acceptable and cost-effective operational bait.


2006 ◽  
Vol 82 (4) ◽  
pp. 579-590 ◽  
Author(s):  
John H Borden ◽  
Anna L Birmingham ◽  
Jennifer S Burleigh

Experiments were conducted near Williams Lake and Quesnel, BC in 2003 to evaluate the effectiveness of the anti-aggregation pheromone verbenone and a three-component non-host volatile (NHV) blend (E-2- and Z-3-hexen-1-ol and benzyl alcohol) in deterring attack of lodgepole pines, Pinus contorta var. latifolia Engelmann, by the mountain pine beetle, Dendroctonus ponderosae Hopkins. In 0.16-ha square plots, with a pheromone-baited tree in the centre and 16 release points at 10-m centres, either verbenone (in a polyurethane gel inside plastic membrane pouches, released at ca. 100 mg/day) or the NHVs (released from separate bubble caps at ca. 1.2 mg/day) deterred attack, but efficacy was not increased by combining them. When deployed from 25 release points at 10-m centres in 0.25-ha square plots, verbenone plus NHVs were effective in deterring attack in some (but not all) cases, when compared to attack in a 25-m wide band around the treated zone. In a test of the push-pull tactic, verbenone plus the NHV blend were tested in a 10-replicate experiment with 100, 44.4 or 25 release points/ha at 10-, 15- or 20-m centres, respectively, in a 1-ha square central zone surrounded by a 3-ha, 50-m-wide band containing 12 pheromone-baited lodgepole pines 50 m apart. Other treatments were pheromonebaited trees alone, and an untreated control. In the three push-pull treatments (but not the bait only or control treatments), 28 of 30 replicates had significantly more mass-attacked trees in the pheromone-baited outer 3 ha than in the inner ha treated with verbenone plus NHVs. The percentage of available trees ≥ 17.5 cm diameter at breast height (dbh) that were mass-attacked was < 10% in 5, 4 and 3 of 10 replicates when verbenone plus NHVs were deployed at 10-, 15- and 20-m centres, respectively, and was < 10% in two each of the bait only and control replicates. The mean ratios of newly-attacked green trees in 2003 to red trees killed in 2002 were significantly lower in the inner ha of the 10-m and 15-m centre treatments (2.6 and 2.7, respectively) than 5.9 in the untreated control. Also the pooled percentages of attacked trees that were not mass-attacked were significantly higher in the inner ha of the treatments with centres at 15 m (24.7%) and 10 m (17.6%) than in the other three treatments (all between 12% and 13%). Despite the apparent efficacy in 10-m and 15-m centre treatments, some replicates failed spectacularly. Failure was not significantly related to the incidence of red trees, but was negatively related to density/ha of available trees and positively related to mean dbh. We recommend operational implementation of the push-pull tactic at 10-m or 15-m centres when the density of available lodgepole pines is > 400/ha, the mean dbh is ≤ 25 cm, current attack is ≤ 15%, and the tactic is part of an integrated pest management program that includes sanitation harvesting. Using verbenone alone at 15-m centres would cost $380/ha (CAD), excluding labour. Key words: mountain pine beetle, Dendroctonus ponderosae, lodgepole pine, Pinus contorta var. latifolia, pheromones, semiochemicals, pest management


1986 ◽  
Vol 16 (5) ◽  
pp. 1036-1040 ◽  
Author(s):  
R. H. Miller ◽  
A. A. Berryman

Healthy lodgepole pine trees (Pinuscontorta Dougl. var. latifolia Engelm.) were girdled on the lower trunk in patterns designed to selectively eliminate the influence of materials transported from the roots, lateral tissues, and crown. Titres of soluble sugars and starch observed in areas isolated by girdling were significantly lower than those observed in areas open to the upper bole and crown. Corresponding decreases were observed in the numbers of Dendroctonusponderosae Hopkins attacking those areas.


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.


2007 ◽  
Vol 42 (3) ◽  
pp. 345-353 ◽  
Author(s):  
Diana L. Six ◽  
Joel Adams

We investigated whether white pine blister rust (Cronartium ribicola) (J.C. Fischer in Rabenh.) severity, tree diameter at breast height (DBH), bark and phloem thickness, and sapwood moisture content influence the preference of the mountain pine beetle (Dendroctonus ponderosae Hopkins) for individual trees of whitebark (Pinus albicaulis Engelm.) and lodgepole pine (P. contorta Loud.). We measured these variables at 5 sites in Montana and Idaho and found a significant relationship between blister rust severity and attack of trees by D. ponderosae, with trees exhibiting greater blister rust severity being more likely to be attacked by the beetle. Sapwood moisture content was negatively correlated (P = 0.0004) with blister rust severity indicating that as severity increases there is an increasingly negative effect on water relations within the tree. Sapwood moisture content was significantly lower in P. albicaulis than in P. contorta at sites with beetle activity suggesting that there may be an interaction between blister rust severity and drought stress that, in turn, may affect beetle preference. DBH and bark and phloem thickness did not appear to influence beetle preference for individual trees. As blister rust spreads in P. albicaulis stands across the western U.S., this may translate to increasing levels of beetle-caused mortality in these areas.


1987 ◽  
Vol 2 (4) ◽  
pp. 114-116 ◽  
Author(s):  
Patrick J. Shea ◽  
Mark McGregor

Abstract A large-scale field experiment was conducted on the Flathead National Forest, Montana, to evaluate the efficacy of 0.5%, 1.0%, and 2.0% formulations of Sevimol® and Sevin brand XLR® for protecting individual lodgepole pines (Pinus contorta var. latifolia Engelm.) from attack by mountain pine beetles (Dendroctonus ponderosae Hopk.). All concentrations and formulations were highly effective (>95%) in protecting lodgepole pine trees from lethal attack by mountain pine beetle for 1 year, and the 1% and 2% concentrations were effective (>90%) for 2 years. West. J. Appl. For. 2(4):114-116, October 1987


1999 ◽  
Vol 131 (6) ◽  
pp. 825-827 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton ◽  
T.L. Shore

Lodgepole pines, Pinus contorta var. contorta Engelmann, killed by mountain pine beetle, Dendroctonus ponderosae Hopkins, are often subsequently infested by other scolytid species (Safranyik et al. 1996). Ips pini (Say) breeds in the phloem region of the main bole and larger branches in areas not occupied by mountain pine beetle. Adults emerge in the fall and drop to overwinter in the duff near the bases of their brood trees (Safranyik et al. 1996). Hylurgops porosus (LeConte) infests lodgepole pine (Keen 1952; Bright 1976) stumps or severely weakened trees near the root collar and in large roots (Wood 1982). We examined the pattern of emergence of I. pini and H. porosus from the duff around infested trees to describe changes in density over distance from the trees.


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