Responses of Engelmann spruce to inoculation with Leptographium abietinum, a symbiotic fungus of the North American spruce beetle

2020 ◽  
Vol 50 (5) ◽  
pp. 465-472
Author(s):  
Jane E. Stewart ◽  
Franklin L. Harris ◽  
Kristen Otto ◽  
Thomas Seth Davis
Keyword(s):  
North American ◽  
Water Availability ◽  
Bark Beetles ◽  
Environmental Variability ◽  
Host Tree ◽  
Symbiotic Fungus ◽  
Engelmann Spruce ◽  
Defensive Responses ◽  
Tree Survival ◽  
Spruce Beetle

Symbiotic fungi associated with tree-killing bark beetles can alter host-tree physiology with consequences for tree survival, and symbiont genetic variation and environmental variability may impact these interactions. Here, we test whether multiple genetically distinct isolates of a symbiotic fungus (Leptographium abietinum (Peck) M.J. Wingf.) associated with North American spruce beetle (Dendroctonus rufipennis (Kirby, 1837)) vary in their ability to manifest defensive responses consistent with disease symptoms in seedlings of Engelmann spruce (Picea engelmannii Parry ex Engelm.), a primary host-tree species for the beetle–fungus complex in North America. Our experiments incorporate variation in both host-tree water availability and host defenses (phloem monoterpene concentration). Three central findings emerged: (i) isolates varied considerably in their effects on host trees — inoculation with L. abietinum isolates from Colorado caused significantly larger phloem lesions than isolates from Wyoming, though all isolates caused phloem oxidation; (ii) neither water availability nor spruce phloem monoterpene concentrations impacted lesion formation; and (iii) both inoculation with L. abietinum and water deficit inhibited the formation of callus tissue at wound sites. We conclude that L. abietinum isolates vary in their virulence and that inoculation is not lethal but may benefit beetles by altering tree defensive responses.

Evidence for multiple ecological roles of Leptographium abietinum, a symbiotic fungus associated with the North American spruce beetle

2019 ◽  
Vol 38 ◽  
pp. 62-70 ◽  
Author(s):  
Thomas S. Davis ◽  
Jane E. Stewart ◽  
Andrew Mann ◽  
Clifford Bradley ◽  
Richard W. Hofstetter
Keyword(s):  
North American ◽  
Symbiotic Fungus ◽  
The North ◽  
Spruce Beetle ◽  
Ecological Roles

Evaluations of Bole Injections for Protecting Engelmann Spruce from Mortality Attributed to Spruce Beetle (Coleoptera: Curculionidae) in the Intermountain West

2020 ◽  
Vol 55 (3) ◽  
pp. 301-309
Author(s):  
Christopher J. Fettig ◽  
A. Steven Munson ◽  
Donald M. Grosman ◽  
Darren C. Blackford
Keyword(s):  
Bark Beetles ◽  
Tree Mortality ◽  
Crop Protection ◽  
Tree Age ◽  
Picea Engelmannii ◽  
Future Research ◽  
Emamectin Benzoate ◽  
Dendroctonus Rufipennis ◽  
Engelmann Spruce ◽  
Spruce Beetle

Abstract Bark beetles are important disturbance agents in coniferous forests, and spruce beetle, Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae), is one of the more notable species causing landscape-level tree mortality in western North America. We evaluated the efficacy of bole injections of emamectin benzoate (TREE-äge®; Arborjet Inc., Woburn, MA) alone and combined with propiconazole (Alamo®; Syngenta Crop Protection Inc., Wilmington, DE) for protecting Engelmann spruce, Picea engelmannii Parry ex Engelmann (Pinales: Pinaceae), from mortality attributed to colonization by D. rufipennis. Two injection periods in 2013 (the spring and fall of the year prior to trees first being challenged by D. rufipennis in 2014) and distributions of injection points (7.6- and 15.2-cm spacings) were evaluated. Tree mortality was monitored over a 3-yr period (2014–2017). Emamectin benzoate injected in spring at a narrow spacing (7.6 cm) was the only effective treatment. Two (but not three) field seasons of protection can be expected with a single injection of this treatment. We discuss the implications of these and other results regarding the use of emamectin benzoate and propiconazole for protecting western conifers from mortality attributed to bark beetles, and provide suggestions for future research. A table summarizing the appropriate timing of treatments in different bark beetle/host systems is provided.

Evaluation of funnel traps for estimating tree mortality and associated population phase of spruce beetle in Utah

2006 ◽  
Vol 36 (10) ◽  
pp. 2574-2584 ◽  
Author(s):  
E Matthew Hansen ◽  
Barbara J Bentz ◽  
A Steven Munson ◽  
James C Vandygriff ◽  
David L Turner
Keyword(s):  
Bark Beetles ◽  
Tree Mortality ◽  
Classification Tree ◽  
Recursive Partitioning ◽  
Dendroctonus Rufipennis ◽  
Beetle Population ◽  
Engelmann Spruce ◽  
Spruce Beetle ◽  
Funnel Trap ◽  
Spruce Mortality

Although funnel traps are routinely used to manage bark beetles, little is known regarding the relationship between trap captures and tree mortality near the trap. We conducted a 4 year study in Utah to examine the correlation between funnel-trap captures of spruce beetle (Dendroctonus rufipennis Kirby) and mortality of Engelmann spruce (Picea engelmannii Parry ex Engelm.) within a 10 ha block of the trap. Using recursive partitioning tree analyses, rules were developed for predicting spruce mortality and associated levels of beetle population phase (endemic or epidemic), in the current year and subsequent year, for a given level of trap captures. Although model predictions of infested-stem counts had large variances, our results suggest that funnel-trap captures can be reliably used to estimate relative levels of tree mortality, expressed as spruce beetle population phase. Classification-tree analyses indicate that captures of ~842 spruce beetles during a season (late May to mid-August) from a single funnel trap represent a threshold between endemic (<2 mass-attacked stems/ha) and epidemic conditions (≥2 mass-attacked stems/ha) for either the current or the subsequent year relative to deployment of the funnel trap. Likewise, a lack of infested hosts within 10 m of a funnel trap, also known as spillover, was associated with endemic conditions, whereas trees attacked near the trap correlated with epidemic conditions.

Engelmann Spruce Chemotypes in Colorado and their Effects on Symbiotic Fungi Associated with the North American Spruce Beetle

2018 ◽  
Vol 44 (6) ◽  
pp. 601-610 ◽  
Author(s):  
Thomas Seth Davis ◽  
Fiona B. Horne ◽  
Jens C. Yetter ◽  
Jane E. Stewart
Keyword(s):  
North American ◽  
Engelmann Spruce ◽  
The North ◽  
Spruce Beetle ◽  
Symbiotic Fungi

WOODPECKER PREDATION ON BARK BEETLES IN ENGELMANN SPRUCE LOGS AS RELATED TO STAND DENSITY

1970 ◽  
Vol 102 (11) ◽  
pp. 1345-1354 ◽  
Author(s):  
Roland S. Shook ◽  
Paul H. Baldwin
Keyword(s):  
Bark Beetles ◽  
Stand Density ◽  
Picea Engelmannii ◽  
Spruce Forest ◽  
Engelmann Spruce ◽  
Dense Forest ◽  
Open Forest ◽  
Spruce Beetle

Abstract Eighty Engelmann spruce logs (Picea engelmannii Parry), which were distributed in open (bulldozed to clearcut), semi-open (selectively cut), and dense (uncut) spruce forest, were infested with Dendroctonus obesus (Mann.) and Ips pilifrons Sw. and fed upon by northern three-toed and hairy woodpeckers. Sections of the infested boles were covered with screen to prevent woodpecker feeding and all logs were left in the field over one winter and through the following summer. By spring, the spruce beetle brood was reduced approximately 50% in all three forest areas. By fall, the spruce beetle brood suffered a 71, 83 and 52% reduction in the open, semi-open and dense forest, respectively. Spruce beetles appeared to be in greatest numbers in the semi-open forest, resulting in the greatest woodpecker predation there. Woodpeckers did not feed in the open meadows. Estimates in the spring, before the Ips emerged from the logs, showed that woodpeckers reduced the Ips brood by 76 and 11% in the open and semi-open forest, respectively. Ips were not found in dense forest or in meadows.

scholarly journals Apparent Tolerance of Low Water Availability in Temperate Asian Bamboos1

2018 ◽  
Vol 36 (1) ◽  
pp. 7-13
Author(s):  
Melissa C. Smith ◽  
Richard N. Mack
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Use ◽  
North American ◽  
Water Availability ◽  
Irrigation Treatment ◽  
Bamboo Species ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Pleioblastus Chino

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.

scholarly journals Understanding and Defining Mortality in Western Conifer Forests

2007 ◽  
Vol 22 (2) ◽  
pp. 105-115 ◽  
Author(s):  
Gregory M. Filip ◽  
Craig L. Schmitt ◽  
Donald W. Scott ◽  
Stephen A. Fitzgerald
Keyword(s):  
Bark Beetles ◽  
Tree Mortality ◽  
Water Movement ◽  
High Elevation ◽  
Regression Equations ◽  
Conifer Forests ◽  
Dead Tree ◽  
Related Factors ◽  
Tree Survival ◽  
Considerable Controversy

Abstract Tree mortality in western conifer forests is a complex process involving several related factors. Conifer mortality tends to be more common in high-elevation forests where stress from weather, insects, and disease result in higher rates of mortality and in the drier interior forests where mortality from fire, insects, and disease are common. Immediate mortality from fire damage may be obvious, but currently there is considerable controversy about labeling fire-injured green trees as dead that have a high probability of experiencing delayed mortality. Trees die when carbohydrates used in respiration exceed those produced in photosynthesis or water movement is impaired, the tree desiccates, and photosynthesis ceases. Immediate or delayed tree mortality may be directly due to biotic or abiotic causes and may be affected by previous damage, current condition (vigor), and attack by secondary agents such as bark beetles. A particular pathogen or insect usually attacks, damages, or kills only one portion of a tree. Trees that are damaged or attacked by pests and expected to have a dead or nonfunctional root system or a nonfunctional stem within 5 years may be considered either dead or death is imminent. Numerous studies have produced logistic regression equations or other statistical models to help determine probability of tree survival. We define and propose that a “dead tree” designation is justified for most species when at least three of the four quadrants from around the base of the root collar has cambium, inner bark, or phloem that are discolored and dead. For large ponderosa pines, a dead tree has all four quadrants with dead cambium.

DIFFERENTIAL BIOACTIVITY OF CONOPHTHORIN ON FOUR SPECIES OF NORTH AMERICAN BARK BEETLES (COLEOPTERA: SCOLYTIDAE)

2000 ◽  
Vol 132 (5) ◽  
pp. 649-653 ◽  
Author(s):  
Dezene P.W. Huber ◽  
John H. Borden ◽  
Nicole L. Jeans-Williams ◽  
Regine Gries
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Dependent Manner ◽  
Dendroctonus Pseudotsugae ◽  
Dendroctonus Rufipennis ◽  
Pine Engraver ◽  
Dryocoetes Confusus ◽  
Baited Traps ◽  
Spruce Beetle ◽  
Dose Dependent

AbstractThe angiosperm bark volatile, conophthorin, was tested at release rates of 3.0 and 0.3 mg/24 h against the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, the spruce beetle, Dendroctonus rufipennis (Kirby), the pine engraver, Ips pint (Say), and the western balsam bark beetle, Dryocoetes confusus Swaine (all Coleoptera: Scolytidae). The responses of D. pseudotsugae, I. pini, and (in one of two experiments) female D. confusus to attractant-baited traps were disrupted by conophthorin in a dose-dependent manner. Dendroctonus rufipennis was not disrupted by conophthorin. Our results extend the repellent bioactivity of conophthorin to Ips DeGeer spp. and confirm earlier experiments with D. pseudotsugae. Conophthorin may have some utility in protecting susceptible timber from bark beetle attack.

Sign in / Sign up

Export Citation Format

Share Document