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Nadir Erbilgin - One of the best experts on this subject based on the ideXlab platform.
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soil available water holding capacity can alter the reproductive performance of mountain Pine beetle coleoptera curculionidae in Jack Pine pinales pinaceae through phloem nitrogen concentration
Environmental Entomology, 2019Co-Authors: Altaf Hussain, Gail Classens, Sydne Guevararozo, Nadir ErbilginAbstract:Mountain Pine beetle (Dendroctonus ponderosae Hopkins, Coleoptera: Curculionidae, Scolytidae) has recently invaded novel Jack Pine (Pinus banksiana Lamb., Pinales: Pinaceae) forests in western Canada. Jack Pine seems to be a suitable host for mountain Pine beetle, but how growing conditions influence Jack Pine's quality as a host, and hence, its susceptibility for mountain Pine beetle, is unknown. Specifically, how soil nutrient concentrations and available water holding capacity (AWHC) affect Jack Pine quality should be investigated. Host plant quality is an important determinant of mountain Pine beetle host colonization and reproduction and is usually assessed by primary (nutrients) and secondary (defense chemistry) constituents of host phloem. We evaluated mountain Pine beetle host acceptance and brood production by recording the percentage of female mountain Pine beetle that entered the phloem and oviposited in 30 Jack Pine bolts from two sites that differed in soil nutrient concentrations and AWHC. We also compared the concentrations of phloem nutrients and defense monoterpenes among the selected trees and found that trees at the Low AWHC site had higher amounts of nitrogen, phosphorus, and potassium. Monoterpene concentrations did not differ among trees at the two sites. Host acceptance by and brood production of mountain Pine beetle were greater in bolts from the Low AWHC site. We conclude that AWHC of the soil may influence mountain Pine beetle host acceptance and brood production through altering host plant quality, particularly nitrogen in the phloem, and will potentially influence any further range expansion of the beetle in eastern North America.
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dwarf mistletoe infection in Jack Pine alters growth defense relationships
Tree Physiology, 2018Co-Authors: Jennifer G Klutsch, Nadir ErbilginAbstract:Trees utilize a combination of chemical and anatomical defenses against a myriad of attacking organisms. However, persistent pathogen infection that alters resource acquisition may impact growth and defense relationships, which could have consequences for tree resistance. We characterized systemic chemical and anatomical changes in Jack Pine (Pinus banksiana) in response to infection by the parasitic plant dwarf mistletoe (Arceuthobium americanum) and identified how the growth-defense relationship is altered due to infection severity. Our study found that the growth and defense relationship in Jack Pine was altered due to infection and that chemical defenses in the phloem received a relatively higher priority than radial growth and anatomical defenses. Chemical defenses in the phloem had a non-linear relationship with infection severity with increasing concentrations of monoterpenes in trees with moderate infection and decreasing concentrations at high infection. In contrast, both radial growth and vertical resin duct production decreased with increasing infection severity. While constitutive resin duct counts and many monoterpene compound concentrations were positively correlated, this relationship was not maintained in infected trees. Furthermore, radial growth and basal area increment was positively correlated with resin duct production and monoterpene concentration in non-infected trees but had fewer relationships in severely infected trees. We conclude that while both chemical and anatomical defenses may be used as indicators for potential resistance to biotic stress in Pines, changes in resource allocation patterns between these defenses after infection will likely have consequences on tree resistance to subsequent biotic attacks.
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a native parasitic plant systemically induces resistance in Jack Pine to a fungal symbiont of invasive mountain Pine beetle
Journal of Chemical Ecology, 2017Co-Authors: Jennifer G Klutsch, Ahmed Najar, Patrick Sherwood, Pierluigi Bonello, Nadir ErbilginAbstract:Conifer trees resist pest and pathogen attacks by complex defense responses involving different classes of defense compounds. However, it is unknown whether prior infection by biotrophic pathogens can lead to subsequent resistance to necrotrophic pathogens in conifers. We used the infection of Jack Pine, Pinus banksiana, by a common biotrophic pathogen dwarf mistletoe, Arceuthobium americanum, to investigate induced resistance to a necrotrophic fungus, Grosmannia clavigera, associated with the mountain Pine beetle, Dendroctonus ponderosae. Dwarf mistletoe infection had a non-linear, systemic effect on monoterpene production, with increasing concentrations at moderate infection levels and decreasing concentrations at high infection levels. Inoculation with G. clavigera resulted in 33 times higher monoterpene concentrations and half the level of phenolics in the necrotic lesions compared to uninoculated control trees. Monoterpene production following dwarf mistletoe infection seemed to result in systemic induced resistance, as trees with moderate disease severity were most resistant to G. clavigera, as evident from shorter lesion lengths. Furthermore, trees with moderate disease severity had the highest systemic but lowest local induction of α-Pinene after G. clavigera inoculation, suggesting a possible tradeoff between systemically- and locally-induced defenses. The opposing effects to inoculation by G. clavigera on monoterpene and phenolic levels may indicate the potential for biosynthetic tradeoffs by the tree between these two major defense classes. Our results demonstrate that interactions between a biotrophic parasitic plant and a necrotrophic fungus may impact mountain Pine beetle establishment in novel Jack Pine forests through systemic effects mediated by the coordination of Jack Pine defense chemicals.
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Fatty Acid Composition of Novel Host Jack Pine Do Not Prevent Host Acceptance and Colonization by the Invasive Mountain Pine Beetle and Its Symbiotic Fungus.
PLOS ONE, 2016Co-Authors: Guncha Ishangulyyeva, Ahmed Najar, Jonathan M. Curtis, Nadir ErbilginAbstract:Fatty acids are major components of plant lipids and can affect growth and development of insect herbivores. Despite a large literature examining the roles of fatty acids in conifers, relatively few studies have tested the effects of fatty acids on insect herbivores and their microbial symbionts. Particularly, whether fatty acids can affect the suitability of conifers for insect herbivores has never been studied before. Thus, we evaluated if composition of fatty acids impede or facilitate colonization of Jack Pine (Pinus banksiana) by the invasive mountain Pine beetle (Dendroctonus ponderosae) and its symbiotic fungus (Grosmannia clavigera). This is the first study to examine the effects of tree fatty acids on any bark beetle species and its symbiotic fungus. In a novel bioassay, we found that plant tissues (hosts and non-host) amended with synthetic fatty acids at concentrations representative of Jack Pine were compatible with beetle larvae. Likewise, G. clavigera grew in media amended with lipid fractions or synthetic fatty acids at concentrations present in Jack Pine. In contrast, fatty acids and lipid composition of a non-host were not suitable for the beetle larvae or the fungus. Apparently, concentrations of individual, rather than total, fatty acids determined the suitability of Jack Pine. Furthermore, sampling of host and non-host tree species across Canada demonstrated that the composition of Jack Pine fatty acids was similar to the different populations of beetle’s historical hosts. These results demonstrate that fatty acids composition compatible with insect herbivores and their microbial symbionts can be important factor defining host suitability to invasive insects.
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the effect of water limitation on volatile emission tree defense response and brood success of dendroctonus ponderosae in two Pine hosts lodgepole and Jack Pine
Frontiers in Ecology and Evolution, 2016Co-Authors: Inka Lusebrink, Nadir Erbilgin, Maya L EvendenAbstract:The mountain Pine beetle (MPB; Dendroctonus ponderosae) has recently expanded its range from lodgepole Pine forest into the lodgepole × Jack Pine hybrid zone in central Alberta, within which it has attacked pure Jack Pine. This study tested the effects of water limitation on tree defense response of mature lodgepole and Jack Pine (Pinus contorta and Pinus banksiana) trees in the field. Tree defense response was initiated by inoculation of trees with the MPB-associated fungus Grosmannia clavigera and measured through monoterpene emission from tree boles and concentration of defensive compounds in phloem, needles, and necrotic tissues. Lodgepole Pine generally emitted higher amounts of monoterpenes than Jack Pine; particularly from fungal-inoculated trees. Compared to non-inoculated trees, fungal inoculation increased monoterpene emission in both species, whereas water treatment had no effect on monoterpene emission. The phloem of both Pine species contains (-)-α-Pinene, the precursor of the beetle’s aggregation pheromone, however lodgepole Pine contains two times as much as Jack Pine. The concentration of defensive compounds was 70-fold greater in the lesion tissue in Jack Pine, but only 10-fold in lodgepole Pine compared to healthy phloem tissue in each species, respectively. Water-deficit treatment inhibited an increase of L-limonene as response to fungal inoculation in lodgepole Pine phloem. The amount of myrcene in Jack Pine phloem was higher in water-deficit trees compared to ambient trees. Beetles reared in Jack Pine were not affected by either water or biological treatment, whereas beetles reared in lodgepole Pine benefited from fungal inoculation by producing larger and heavier female offspring. Female beetles that emerged from Jack Pine bolts contained more fat than those that emerged from lodgepole Pine, even though lodgepole Pine phloem had a higher nitrogen content than Jack Pine phloem. These results suggest that Jack Pine chemistry is suitable for MPB pheromone production and aggregation on the host tree.
Stith T Gower - One of the best experts on this subject based on the ideXlab platform.
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carbon and nitrogen dynamics of boreal Jack Pine stands with and without a green alder understory
Ecosystems, 1998Co-Authors: Jason G Vogel, Stith T GowerAbstract:We compared the species composition, structure and selected components of the carbon (C) and nitrogen (N) budgets of similar-aged, mature boreal Jack Pine (Pinus banksiana Lamb.) forests with and without green alder [Alnus crispa (Ait.) Pursh.] in two different boreal environments. The C and N content of the overstory biomass components (for example, stem, branch, and foliage), total vegetation, forest floor, and mineral soil were greater (P= 0.05 to P= 0.10) for Jack Pine with alder (JPA) stands than for Jack Pine without alder (JP) stands at both study areas. Jack Pine foliage N isotopic discrimination (δ15N) and annual litterfall N content were significantly greater (P < 0.05) in the JPA than the JP stands at both study areas, suggesting that alder was fixing N and that N availability was greater in the JPA than the JP stands. The greater leaf area index (LAI) and overstory C accumulation in the JPA than the JP stands (P < 0.05) is likely because of the greater N availability in the JPA stands, but the effect of soil texture discontinuity on water availability in the JPA stands can not be dismissed. Percent ground cover by feathermoss varied among the Jack Pine communities and was positively correlated with overstory LAI (r 2= 0.83, P< 0.05). One index of N-use efficiency (NUE), defined as aboveground net primary productivity (ANPP) per litterfall N, was significantly greater (P < 0.05) for the JP than the JPA stands, but a second index of NUE, ANPP/N uptake, did not differ between the two Jack Pine communities. Jack Pine trees growing without alder produced more organic matter per unit of N, but percent N retranslocation from senescing foliage and N mean residence time in the overstory did not differ between the JPA and the JP stands. A conceptual model is presented that illustrates the potential influence of alder on the species composition, structure, and function of boreal Jack Pine forests.
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carbon distribution and aboveground net primary production in aspen Jack Pine and black spruce stands in saskatchewan and manitoba canada
Journal of Geophysical Research, 1997Co-Authors: Stith T Gower, Jason G Vogel, John M Norman, Christopher J Kucharik, S J Steele, T K StowAbstract:The objectives of this study are to (1) characterize the carbon (C) content, leaf area index, and aboveground net primary production (ANPP) for mature aspen, black spruce, and young and mature Jack Pine stands at the southern and northern Boreal Ecosystem-Atmosphere Study (BOREAS) areas and (2) compare net primary production and carbon allocation coefficients for the major boreal forest types of the world. Direct estimates of leaf area index, defined as one half of the total leaf surface area, range from a minimum of 1.8 for Jack Pine forests to a maximum of 5.6 for black spruce forests; stems comprise 5 to 15% of the total overstory plant area. In the BOREAS study, total ecosystem (vegetation plus detritus plus soil) carbon content is greatest in the black spruce forests (445,760–479,380 kg C ha−1), with 87 to 88% of the C in the soil, and is lowest in the Jack Pine stands (68,370–68,980 kg C ha−1) with a similar distribution of carbon in the vegetation and soil. Forest floor carbon content and mean residence time (MRT) also vary more among forest types in a study area than between study areas for a forest type; forest floor MRT range from 16 to 19 years for aspen stands to 28 to 39 years for Jack Pine stands. ANPP differs significantly among the mature forests at each of the BOREAS study areas, ranging from a maximum of 3490 to 3520 kg C ha−1 yr−1 for aspen stands to 1170 to 1220 kg C ha−1 yr−1 for Jack Pine stands. Both net primary production (NPP) and carbon allocation differ between boreal evergreen and deciduous forests in the world, suggesting global primary production models should distinguish between these two forest types. On average, 56% of NPP for boreal forests occurs as detritus and illustrates the need to better understand factors controlling aboveground and below-ground detritus production in boreal forests.
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carbon distribution and aboveground net primary production in aspen Jack Pine and black spruce stands in saskatchewan and manitoba canada
Journal of Geophysical Research, 1997Co-Authors: Stith T Gower, Jason G Vogel, John M Norman, Christopher J Kucharik, S J Steele, T K StowAbstract:The objectives of this study are to (1) characterize the carbon (C) content, leaf area index, and aboveground net primary production (ANPP) for mature aspen, black spruce, and young and mature Jack Pine stands at the southern and northern Boreal Ecosystem-Atmosphere Study (BOREAS) areas and (2) compare net primary production and carbon allocation coefficients for the major boreal forest types of the world. Direct estimates of leaf area index, defined as one half of the total leaf surface area, range from a minimum of 1.8 for Jack Pine forests to a maximum of 5.6 for black spruce forests; stems comprise 5 to 15% of the total overstory plant area. In the BOREAS study, total ecosystem (vegetation plus detritus plus soil) carbon content is greatest in the black spruce forests (445,760–479,380 kg C ha−1), with 87 to 88% of the C in the soil, and is lowest in the Jack Pine stands (68,370–68,980 kg C ha−1) with a similar distribution of carbon in the vegetation and soil. Forest floor carbon content and mean residence time (MRT) also vary more among forest types in a study area than between study areas for a forest type; forest floor MRT range from 16 to 19 years for aspen stands to 28 to 39 years for Jack Pine stands. ANPP differs significantly among the mature forests at each of the BOREAS study areas, ranging from a maximum of 3490 to 3520 kg C ha−1 yr−1 for aspen stands to 1170 to 1220 kg C ha−1 yr−1 for Jack Pine stands. Both net primary production (NPP) and carbon allocation differ between boreal evergreen and deciduous forests in the world, suggesting global primary production models should distinguish between these two forest types. On average, 56% of NPP for boreal forests occurs as detritus and illustrates the need to better understand factors controlling aboveground and below-ground detritus production in boreal forests.
David W Coltman - One of the best experts on this subject based on the ideXlab platform.
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spatial and genetic structure of the lodgepole Jack Pine hybrid zone
Canadian Journal of Forest Research, 2019Co-Authors: Ian Burns, Patrick M A James, David W Coltman, Catherine I CullinghamAbstract:In north-central Alberta, lodgepole Pine (Pinus contorta Dougl. ex Loud. var. latifolia) and Jack Pine (Pinus banksiana Lamb.) form a mosaic hybrid zone, the spatial extent of which remains poorly ...
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effects of introgression on the genetic population structure of two ecologically and economically important conifer species lodgepole Pine pinus contorta var latifolia and Jack Pine pinus banksiana
Genome, 2013Co-Authors: Catherine I Cullingham, Janice E K Cooke, David W ColtmanAbstract:Forest trees exhibit a remarkable range of adaptations to their environment, but as a result of frequent and long-distance gene flow, populations are often only weakly differentiated. Lodgepole and Jack Pine hybridize in western Canada, which adds the opportunity for introgression through hybridization to contribute to population structure and (or) adaptive variation. Access to large sample size, high density SNP datasets for these species would improve our ability to resolve population structure, parameterize introgression, and separate the influence of demography from adaptation. To accomplish this, 454 transcriptome reads for lodgepole and Jack Pine were assembled using Newbler and MIRA, the assemblies mined for SNPs, and 1536 SNPs were selected for typing on lodgepole Pine, Jack Pine, and their hybrids (N = 536). We identified population structure using both Bayesian clustering and discriminate analysis of principle components. Introgressed SNP loci were identified and their influence on observed population structure was assessed. We found that introgressed loci resulted in increased differentiation both within lodgepole and Jack Pine populations. These findings are timely given the recent mountain Pine beetle population expansion in the hybrid zone, and will facilitate future studies of adaptive traits in these ecologically important species.
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characterizing the physical and genetic structure of the lodgepole Pine Jack Pine hybrid zone mosaic structure and differential introgression
Evolutionary Applications, 2012Co-Authors: Catherine I Cullingham, Patrick M A James, Janice E K Cooke, David W ColtmanAbstract:Understanding the physical and genetic structure of hybrid zones can illuminate factors affecting their formation and stability. In north-central Alberta, lodgepole Pine (Pinus contorta Dougl. ex Loud. var. latifolia) and Jack Pine (Pinus banksiana Lamb) form a complex and poorly defined hybrid zone. Better knowledge of this zone is relevant, given the recent host expansion of mountain Pine beetle into Jack Pine. We characterized the zone by genotyping 1998 lodgepole, Jack Pine, and hybrids from British Columbia, Alberta, Saskatchewan, Ontario, and Minnesota at 11 microsatellites. Using Bayesian algorithms, we calculated genetic ancestry and used this to model the relationship between species occurrence and environment. In addition, we analyzed the ancestry of hybrids to calculate the genetic contribution of lodgepole and Jack Pine. Finally, we measured the amount of gene flow between the pure species. We found the distribution of the Pine classes is explained by environmental variables, and these distributions differ from classic distribution maps. Hybrid ancestry was biased toward lodgepole Pine; however, gene flow between the two species was equal. The results of this study suggest that the hybrid zone is complex and influenced by environmental constraints. As a result of this analysis, range limits should be redefined.
T K Stow - One of the best experts on this subject based on the ideXlab platform.
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carbon distribution and aboveground net primary production in aspen Jack Pine and black spruce stands in saskatchewan and manitoba canada
Journal of Geophysical Research, 1997Co-Authors: Stith T Gower, Jason G Vogel, John M Norman, Christopher J Kucharik, S J Steele, T K StowAbstract:The objectives of this study are to (1) characterize the carbon (C) content, leaf area index, and aboveground net primary production (ANPP) for mature aspen, black spruce, and young and mature Jack Pine stands at the southern and northern Boreal Ecosystem-Atmosphere Study (BOREAS) areas and (2) compare net primary production and carbon allocation coefficients for the major boreal forest types of the world. Direct estimates of leaf area index, defined as one half of the total leaf surface area, range from a minimum of 1.8 for Jack Pine forests to a maximum of 5.6 for black spruce forests; stems comprise 5 to 15% of the total overstory plant area. In the BOREAS study, total ecosystem (vegetation plus detritus plus soil) carbon content is greatest in the black spruce forests (445,760–479,380 kg C ha−1), with 87 to 88% of the C in the soil, and is lowest in the Jack Pine stands (68,370–68,980 kg C ha−1) with a similar distribution of carbon in the vegetation and soil. Forest floor carbon content and mean residence time (MRT) also vary more among forest types in a study area than between study areas for a forest type; forest floor MRT range from 16 to 19 years for aspen stands to 28 to 39 years for Jack Pine stands. ANPP differs significantly among the mature forests at each of the BOREAS study areas, ranging from a maximum of 3490 to 3520 kg C ha−1 yr−1 for aspen stands to 1170 to 1220 kg C ha−1 yr−1 for Jack Pine stands. Both net primary production (NPP) and carbon allocation differ between boreal evergreen and deciduous forests in the world, suggesting global primary production models should distinguish between these two forest types. On average, 56% of NPP for boreal forests occurs as detritus and illustrates the need to better understand factors controlling aboveground and below-ground detritus production in boreal forests.
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carbon distribution and aboveground net primary production in aspen Jack Pine and black spruce stands in saskatchewan and manitoba canada
Journal of Geophysical Research, 1997Co-Authors: Stith T Gower, Jason G Vogel, John M Norman, Christopher J Kucharik, S J Steele, T K StowAbstract:The objectives of this study are to (1) characterize the carbon (C) content, leaf area index, and aboveground net primary production (ANPP) for mature aspen, black spruce, and young and mature Jack Pine stands at the southern and northern Boreal Ecosystem-Atmosphere Study (BOREAS) areas and (2) compare net primary production and carbon allocation coefficients for the major boreal forest types of the world. Direct estimates of leaf area index, defined as one half of the total leaf surface area, range from a minimum of 1.8 for Jack Pine forests to a maximum of 5.6 for black spruce forests; stems comprise 5 to 15% of the total overstory plant area. In the BOREAS study, total ecosystem (vegetation plus detritus plus soil) carbon content is greatest in the black spruce forests (445,760–479,380 kg C ha−1), with 87 to 88% of the C in the soil, and is lowest in the Jack Pine stands (68,370–68,980 kg C ha−1) with a similar distribution of carbon in the vegetation and soil. Forest floor carbon content and mean residence time (MRT) also vary more among forest types in a study area than between study areas for a forest type; forest floor MRT range from 16 to 19 years for aspen stands to 28 to 39 years for Jack Pine stands. ANPP differs significantly among the mature forests at each of the BOREAS study areas, ranging from a maximum of 3490 to 3520 kg C ha−1 yr−1 for aspen stands to 1170 to 1220 kg C ha−1 yr−1 for Jack Pine stands. Both net primary production (NPP) and carbon allocation differ between boreal evergreen and deciduous forests in the world, suggesting global primary production models should distinguish between these two forest types. On average, 56% of NPP for boreal forests occurs as detritus and illustrates the need to better understand factors controlling aboveground and below-ground detritus production in boreal forests.
Inka Lusebrink - One of the best experts on this subject based on the ideXlab platform.
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the effect of water limitation on volatile emission tree defense response and brood success of dendroctonus ponderosae in two Pine hosts lodgepole and Jack Pine
Frontiers in Ecology and Evolution, 2016Co-Authors: Inka Lusebrink, Nadir Erbilgin, Maya L EvendenAbstract:The mountain Pine beetle (MPB; Dendroctonus ponderosae) has recently expanded its range from lodgepole Pine forest into the lodgepole × Jack Pine hybrid zone in central Alberta, within which it has attacked pure Jack Pine. This study tested the effects of water limitation on tree defense response of mature lodgepole and Jack Pine (Pinus contorta and Pinus banksiana) trees in the field. Tree defense response was initiated by inoculation of trees with the MPB-associated fungus Grosmannia clavigera and measured through monoterpene emission from tree boles and concentration of defensive compounds in phloem, needles, and necrotic tissues. Lodgepole Pine generally emitted higher amounts of monoterpenes than Jack Pine; particularly from fungal-inoculated trees. Compared to non-inoculated trees, fungal inoculation increased monoterpene emission in both species, whereas water treatment had no effect on monoterpene emission. The phloem of both Pine species contains (-)-α-Pinene, the precursor of the beetle’s aggregation pheromone, however lodgepole Pine contains two times as much as Jack Pine. The concentration of defensive compounds was 70-fold greater in the lesion tissue in Jack Pine, but only 10-fold in lodgepole Pine compared to healthy phloem tissue in each species, respectively. Water-deficit treatment inhibited an increase of L-limonene as response to fungal inoculation in lodgepole Pine phloem. The amount of myrcene in Jack Pine phloem was higher in water-deficit trees compared to ambient trees. Beetles reared in Jack Pine were not affected by either water or biological treatment, whereas beetles reared in lodgepole Pine benefited from fungal inoculation by producing larger and heavier female offspring. Female beetles that emerged from Jack Pine bolts contained more fat than those that emerged from lodgepole Pine, even though lodgepole Pine phloem had a higher nitrogen content than Jack Pine phloem. These results suggest that Jack Pine chemistry is suitable for MPB pheromone production and aggregation on the host tree.
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the lodgepole Jack Pine hybrid zone in alberta canada a stepping stone for the mountain Pine beetle on its journey east across the boreal forest
Journal of Chemical Ecology, 2013Co-Authors: Nadir Erbilgin, Inka Lusebrink, Maya L EvendenAbstract:Historical data show that outbreaks of the tree killing mountain Pine beetle are often preceded by periods of drought. Global climate change impacts drought frequency and severity and is implicated in the range expansion of the mountain Pine beetle into formerly unsuitable habitats. Its expanded range has recently reached the lodgepole × Jack Pine hybrid zone in central Alberta, Canada, which could act as a transition from its historical lodgepole Pine host to a Jack Pine host present in the boreal forest. This field study tested the effects of water limitation on chemical defenses of mature trees against mountain Pine beetle-associated microorganisms and on beetle brood success in lodgepole × Jack Pine hybrid trees. Tree chemical defenses as measured by monoterpene emission from tree boles and monoterpene concentration in needles were greater in trees that experienced water deficit compared to well-watered trees. Myrcene was identified as specific defensive compound, since it significantly increased upon inoculation with dead mountain Pine beetles. Beetles reared in bolts from trees that experienced water deficit emerged with a higher fat content, demonstrating for the first time experimentally that drought conditions benefit mountain Pine beetles. Further, our study demonstrated that volatile chemical emission from tree boles and phloem chemistry place the hybrid tree chemotype in-between lodgepole Pine and Jack Pine, which might facilitate the host shift from lodgepole Pine to Jack Pine.