Fire-injured ponderosa pine provide a pulsed resource for bark beetles

2012 ◽  
Vol 42 (12) ◽  
pp. 2022-2036 ◽  
Author(s):  
Ryan S. Davis ◽  
Sharon Hood ◽  
Barbara J. Bentz

Bark beetles can cause substantial mortality of trees that would otherwise survive fire injuries. Resin response of fire-injured northern Rocky Mountain ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and specific injuries that contribute to increased bark beetle attack susceptibility and brood production are unknown. We monitored ponderosa pine mortality and resin flow and bark beetle colonization and reproduction following a prescribed fire in Idaho and a wildfire in Montana. The level of fire-caused tree injury differed between the two sites, and the level of tree injury most susceptible to bark beetle attack and colonization also differed. Strip-attacked trees alive 3 years post-fire had lower levels of bole and crown injury than trees mass attacked and killed by bark beetles, suggesting that fire-injured trees were less well defended. Brood production of western pine beetle ( Dendroctonus brevicomis LeConte) did not differ between fire-injured and uninjured trees, although mountain pine beetle ( Dendroctonus ponderosae Hopkins) brood production was low in both tree types, potentially due to competition with faster developing bark beetle species that also colonized trees. Despite a large number of live trees remaining at both sites, bark beetle response to fire-injured trees pulsed and receded within 2 years post-fire, potentially due to a limited number of trees that could be easily colonized.

2010 ◽  
Vol 25 (4) ◽  
pp. 181-185 ◽  
Author(s):  
Donald M. Grosman ◽  
Christopher J. Fettig ◽  
Carl L. Jorgensen ◽  
A. Steven Munson

Abstract Bark beetles (Coleoptera: Curculionidae, Scolytinae) are important tree mortality agents in western coniferous forests. Protection of individual trees from bark beetle attack has historically involved applications of liquid formulations of contact insecticides to the tree bole using hydraulic sprayers. More recently, researchers looking for more portable and environmentally safe alternatives have examined the effectiveness of injecting small quantities of systemic insecticides directly into trees. In this study, we evaluated trunk injections of experimental formulations of emamectin benzoate and fipronil for preventing tree mortality due to attack by western pine beetle (Dendroctonus brevicomis LeConte) on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) in California, mountain pine beetle (Dendroctonus ponderosae Hopkins) on lodgepole pine (Pinus contorta Dougl. ex Loud.) in Idaho, and spruce beetle (D. rufipennis [Kirby]) on Engelmann spruce (Picea engelmannii Parry ex Engelm.) in Utah. Fipronil appeared ineffective for protecting P. ponderosa from mortality due to D. brevicomis over the 3 years in California because of insufficient mortality of untreated, baited control trees the first 2 years and high mortality of the fipronil-treated trees in the third year. Emamectin benzoate was effective in providing protection of P. ponderosa from D. brevicomis during the third year following a single application. To our knowledge, this is the first demonstration of the successful application of a systemic insecticide for protecting individual conifers from mortality due to bark beetle attack in the western United States. Estimates of efficacy could not be made during both field seasons in P. contorta because of insufficient mortality in control trees. Both emamectin benzoate and fipronil were ineffective for protecting P. engelmannii from D. rufipennis. Lower ambient and soil temperatures and soil moisture may have limited chemical movement and thus efficacy at the Idaho and Utah sites.


2008 ◽  
Vol 38 (5) ◽  
pp. 924-935 ◽  
Author(s):  
Christopher J. Fettig ◽  
Robert R. Borys ◽  
Stephen R. McKelvey ◽  
Christopher P. Dabney

Mechanical thinning and the application of prescribed fire are commonly used tools in the restoration of fire-adapted forest ecosystems. However, few studies have explored their effects on subsequent amounts of bark beetle caused tree mortality in interior ponderosa pine, Pinus ponderosa Dougl. ex P. & C. Laws. var. ponderosa. In this study, we examined bark beetle responses to creation of midseral (low diversity) and late-seral stages (high diversity) and the application of prescribed fire on 12 experimental units ranging in size from 76 to 136 ha. A total of 9500 (5.0% of all trees) Pinus and Abies trees died 2 years after treatment of which 28.8% (2733 trees) was attributed to bark beetle colonization. No significant difference in the mean percentage of trees colonized by bark beetles was found between low diversity and high diversity. The application of prescribed fire resulted in significant increases in bark beetle caused tree mortality (all species) and for western pine beetle, Dendroctonus brevicomis LeConte, mountain pine beetle, Dendroctonus ponderosae Hopkins, Ips spp., and fir engraver, Scolytus ventralis LeConte, individually. Approximately 85.6% (2339 trees) of all bark beetle caused tree mortality occurred on burned split plots. The implications of these and other results to sustainable forest management are discussed.


1972 ◽  
Vol 50 (9) ◽  
pp. 1943-1945 ◽  
Author(s):  
H. S. Whitney ◽  
F. W. Cobb Jr.

Three fungi—Ceratocystis nigrocarpa Davidson, an unidentified hyphomycete, and an unidentified basidiomycete—were isolated from extensive non-stained areas of sapwood of ponderosa pine infested with western pine beetle, Dendroctonus brevicomis Lec., in California. The two unidentified fungi were also present in the thoracic mycangium of the female beetle while C. nigrocarpa was found only externally on the beetle. The mycangium and its contents are illustrated. Ceratocystis minor (Hedgc.) Hunt, which was also found externally on the beetle but not in the mycangium, was isolated only from scattered patches of blue-stained sapwood. It is suggested that non-staining fungi play a role in causing the death of ponderosa pine trees attacked by D. brevicomis.


1986 ◽  
Vol 64 (7) ◽  
pp. 1507-1509 ◽  
Author(s):  
Thomas M. Pettey ◽  
Charles Gardner Shaw

Isolations of Hymenomycetes on a preferential medium were attempted from preflight pine engraver beetles, Ips pini, and the following in-flight bark beetles: pine engraver beetle, I. pini; western pine beetle, Dendroctonus brevicomis; mountain pine beetle, Dendroctonus ponderosae; and red turpentine beetle, Dendroctonus valens. Thirty pine engraver beetles removed from ponderosa pine slash (preflight) yielded no hymenomycete. However, Hymenomycetes were isolated from 50 of 114 beetles (all species) trapped in flight; Fomitopsis pinicola from 44, and other unidentified suspected Hymenomycetes, from 6. Cryptoporus volvatus was not isolated from any of the in-flight beetles. Since most of these isolates were without clamps (monokaryotic), the beetles may acquire basidiospores after emergence from beetle galleries in coniferous trees as hypothesized previously for the Douglas-fir beetle, Dendroctonus pseudotsugae. The isolation of F. pinicola from all species of in-flight bark beetles indicates that these beetles may be important in the dissemination of this hymenomycete.


2011 ◽  
Vol 41 (5) ◽  
pp. 1031-1046 ◽  
Author(s):  
Chris J.K. MacQuarrie ◽  
Barry J. Cooke

Thinning, the selective removal of some trees from a forest, is one way forest managers can reduce the probability that a forest will be susceptible to attack by bark beetles. Although this method has been shown to be effective, it is not clear whether the effect arises when pre-outbreak populations are small or during the epidemic phase when outbreaks are growing. We adopted a population dynamics approach to determine if the effect of limit or basal area thinning could be observed in the form of differential beetle recruitment using lodgepole pine ( Pinus contorta Dougl. ex Loud.) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) mortality data from previously published studies as a proxy measure of mountain pine beetle ( Dendroctonus ponderosae Hopkins) population size. We found that mountain pine beetle populations exhibit density-dependent population dynamics that are influenced by the silvicultural history of their host’s stand. Thinning did not change the epidemic equilibrium but instead caused a shift in dynamics from linear to nonlinear. In a validation test, the models developed for thinned and unthinned stands predicted reproductive rates in independent locations. These data also suggest the epidemic dynamics of mountain pine beetle may be sensitive to perturbations and to systematic trends associated with climate variability and climate change.


1980 ◽  
Vol 112 (7) ◽  
pp. 725-730 ◽  
Author(s):  
D. J. Goheen ◽  
F. W. Cobb

AbstractThe relationship between bark beetle infestation of ponderosa pine and severity of infection by Ceratocystis wageneri was investigated by closely monitoring 256 trees (136 apparently healthy, 60 moderately diseased, and 60 severely diseased at initiation of study) for beetle infestation from summer 1972 to fall 1975. Disease ratings were updated by periodic examination, and some trees changed disease category during the study. Ninety trees were infested by Dendroctonus brevicomis, D. ponderosae, or both, five by buprestids alone, and one tree died from effects of the pathogen alone. Sixty-two of the beetle-infested trees were severely diseased at time of infestation, 25 were moderately diseased, and only three were apparently healthy. Thus, the results showed that bark beetles were much more likely to infest infected than healthy trees. Among diseased trees, those with advanced infections were most likely to be infested. There was evidence that buprestids (especially Melanophila spp.) and possibly Ips spp. attacked diseased trees prior to Dendroctonus spp. infestation.


2008 ◽  
Vol 23 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Christopher J. Fettig ◽  
Christopher P. Dabney ◽  
Stephen R. McKelvey ◽  
Dezene P.W. Huber

Abstract Nonhost angiosperm volatiles (NAV) and verbenone were tested for their ability to protect individual ponderosa pines, Pinus ponderosa Dougl. ex. Laws., from attack by western pine beetle (WPB), Dendroctonus brevicomis LeConte, and red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae). A combination of (−)-verbenone and eight NAVs [benzyl alcohol, benzaldehyde, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol, and (Z)-2-hexen-1-ol] (NAVV) significantly reduced the density of WPB attacks and WPB successful attacks on attractant-baited trees. A significantly higher percentage of pitchouts (unsuccessful WPB attacks) occurred on NAVV-treated trees during two of three sample dates. In addition, significantly fewer RTB attacks were observed on NAVV-treated trees during all sampling dates. The application of NAVV to individual ponderosa pines significantly reduced tree mortality, with only 4 of 30 attractant-baited trees dying from bark beetle attack while 50% mortality (15/30) was observed in the untreated, baited control. To our knowledge, this is the first report establishing the effectiveness of NAVs and verbenone for protecting individual ponderosa pines from WPB attack.


1958 ◽  
Vol 90 (10) ◽  
pp. 582-584 ◽  
Author(s):  
R. L. Lyon

The sex of the western pine beetle (Dendroctonus brevicomis Lec.) and the mountain pine beetle (Dendroctonus monticolae Hopk.) can be ascertained easily and with 100 percent accuracy by means of a secondary sex character on the seventh abdominal tergite of the male. This character can probably be used with equal accuracy to identify sex in all species of the genus Dendroctonus.The need to distinguish between the sexes of adult bark beetles often arises in studies of biology, behavior, or response. The sexing procedure is laborious when large numbers of beetles are involved and external markings of sex are not known. It is then necessary to dissect each beetle to check the genitalia. Dissection is impossible when iniury to the insect must be avoided.


2021 ◽  
Author(s):  
David Soderberg ◽  
Bethany Kyre ◽  
Pierliugi Bonello ◽  
Barbara Bentz

A key component in understanding plant-insect interactions is the nature of host defenses. Research on defense traits among Pinus species has focused on specialized metabolites and axial resin ducts, but the role of lignin in defense within diverse systems is unclear. We investigated lignin levels in the outer bark and phloem of P. longaeva , P. balfouriana , and P. flexilis ; high elevation species in the western United States known to differ in susceptibility to mountain pine beetle ( Dendroctonus ponderosae ; MPB). Relative to P. flexilis , P. longaeva and P. balfouriana are attacked by MPB less frequently, and MPB brood production in P. longaeva is limited. Because greater lignification of feeding tissues has been shown to provide defense against bark beetles in related genera, such as Picea , we hypothesized that P. longaeva and P. balfouriana would have greater lignin concentrations than P. flexilis . Contrary to expectations, we found that the more MPB-susceptible P. flexilis had greater phloem lignin levels than the less susceptible P. longaeva and P. balfouriana . No differences in outer bark lignin levels among the species were found. We conclude that lignification in Pinus phloem and outer bark is likely not adaptive as a physical defense against MPB.


2003 ◽  
Vol 38 (4) ◽  
pp. 602-611 ◽  
Author(s):  
Daniel R. Miller ◽  
John H. Borden

We conducted seven experiments in stands of mature lodgepole pine in southern British Columbia to elucidate the role of host volatiles in the semiochemical ecology of the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae), with particular reference to the behavioral responses of predators and competing species of bark beetles. Our results demonstrated that the attraction of Ips pini and the bark beetle predators Lasconotus complex LeConte (Colydiidae), Thanasimus undatulus (Say) (Cleridae) and a Corticeus sp. (Tenebrionidae) were increased by 3-carene. In contrast, attraction of the bark beetle Pityogenes knechteli Swaine (Scolytidae) to ipsdienol was interrupted by 3-carene and α-pinene. Attraction of L. complex to ipsdienol was increased by γ-terpinene, a compound attractive to the mountain pine beetle, Dendroctonus ponderosae Hopkins (Scolytidae). Terpinolene interrupted the attraction of I. pini to ipsdienol.


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