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Michael J. Wingfield - One of the best experts on this subject based on the ideXlab platform.
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Multigene phylogenies define Ceratocystiopsis and Grosmannia distinct from Ophiostoma
2016Co-Authors: Renate D. Zipfel, Brenda D Wingfield, Wilhelm Z De Beer, Karin Jacobs, Michael J. WingfieldAbstract:Abstract: Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However
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STUDIES IN MYCOLOGY 55: 75–97. 2006. Multi-gene phylogenies define Ceratocystiopsis and Grosmannia distinct from
2013Co-Authors: Renate D. Zipfel, Brenda D Wingfield, Wilhelm Z De Beer, Karin Jacobs, Michael J. WingfieldAbstract:Abstract: Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However
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Phylogram of Ophiostoma sensulato based on ITS1-ITS2.
2013Co-Authors: Stephen J. Taerum, Wilhelm Z De Beer, Tuan A. Duong, Nancy Gillette, Jiang-hua Sun, Donald R. Owen, Michael J. WingfieldAbstract:Maximum likelihood (ML) phylogram of 75 ophiostomatalean fungi in the genus Ophiostoma sensu lato, two in the genus Fragosphaeria, three in the genus Ceratocystiopsis, nine in the genus Graphilbum, and 11 in the genus Leptographium sensu lato as an outgroup, based on ITS1-ITS2. Each strain is indicated by its species name, the Genbank accession number or CMW culture collection number (if accession number is not available), and a T if the isolate originates from a species’ type specimen. Strains associated with D. valens either from this study or the Chinese studies [54,55] are in bold font, and are followed with the location they were isolated from. Strains are subdivided into species complexes indicated by different colors. Statistical support is given to the left of the nodes, with ML bootstrap proportions on top (only values greater than 75 are shown), and Bayesian posterior probability (PP) values on the bottom (only values greater than 0.90 are shown). * indicates that the ML or PP values were not significant at those nodes.
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Ophiostomatoid fungi associated with the Eastern Himalayan spruce bark beetle (Ips schmutzenhoferi) in Bhutan: Species assemblage and phytopathogenicity
Journal of Agricultural Extension and Rural Development, 2012Co-Authors: Thomas Kirisits, Michael J. Wingfield, Heino Konrad, D. B. ChhetriAbstract:A brief synthesis of recent studies on the ophiostomatoid fungi associated with the Eastern Himalayan spruce bark beetle, Ips schmutzenhoferi and on the pathogenicity of selected fungal associates of this insect to Picea spinulosa and Pinus wallichiana is presented.I. schmutzenhoferi is intimately asso-ciated with ophistomatoid fungi and eleven fungal associates belonging to the genera Ceratocystis, Ceratocystiopsis, Grosmannia, Ophiostoma,Leptographium and Pesotum were documented in a survey in Western Bhutan in 2001. In inoculation experiments with four ophiostomatoid fungi, conducted in 2005, Leptographium sp. 1, the most common fungal associate of I. schmutzenhoferi, displayed high levels of virulence to P. spinulosa. In contrast, P. wallichiana was highly resistant to inoculation with all four fungal species. The pathogenicity trials indicate that fungal associates of I. schmutzenhoferi and especially Leptographium sp. 1 prefer P. spinulosa over P. wallichiana as host, as is true of the insect itself. Key words: Ceratocystis bhutanensis, Ophiostoma sensu lato, blue-stain fungi, fungal associates, insect-fungus symbiosis.
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multi gene phylogenies define Ceratocystiopsis and grosmannia distinct from ophiostoma
Studies in Mycology, 2006Co-Authors: Renate Zipfel, Wilhelm Z De Beer, Brenda D Wingfield, Karin Jacobs, Michael J. WingfieldAbstract:Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However, these species are retained in Ophiostoma until further data for a larger number of species can be obtained to confirm monophyly of the apparent lineages.
Diana L. Six - One of the best experts on this subject based on the ideXlab platform.
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Cascading speciation among mutualists and antagonists in a tree-beetle-fungi interaction.
Proceedings. Biological sciences, 2018Co-Authors: Ryan Bracewell, Dan Vanderpool, Jeffrey M. Good, Diana L. SixAbstract:Cascading speciation is predicted to occur when multiple interacting species diverge in parallel as a result of divergence in one species promoting adaptive differentiation in other species. However, there are few examples where ecological interactions among taxa have been shown to result in speciation that cascades across multiple trophic levels. Here, we test for cascading speciation occurring among the western pine beetle ( Dendroctonus brevicomis ), its primary host tree ( Pinus ponderosa ), and the beetle9s fungal mutualists ( Ceratocystiopsis brevicomi and Entomocorticium sp. B). We assembled genomes for the beetle and a fungal symbiont and then generated reduced representation genomic data (RADseq) from range-wide samples of these three interacting species. Combined with published data for the host tree, we present clear evidence that the tree, the beetle, and the fungal symbionts are all genetically structured into at least two distinct groups that have strongly codiverged with geographical isolation. We then combine our genomic results with diverse population and laboratory-based data to show evidence for reproductive isolation at each level of the cascade and for coevolution of both antagonistic and mutualistic species interactions within this complex network.
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Temperature effects on growth of fungal symbionts of the western pine beetle, Dendroctonus brevicomis
Fungal Ecology, 2015Co-Authors: Joseph C. Dysthe, Ryan Bracewell, Diana L. SixAbstract:Abstract Differences in temperature ranges and optima among poikilothermic partners in symbioses can have profound effects on their interactions and stability. In this study, we investigated how the two mutualist mycangial fungi (Ceratocystiopsis brevicomi and Entomocorticium sp. B) associated with the western pine beetle, Dendroctonus brevicomis, respond to temperature in vitro. Little variability in growth rate at the various temperatures tested occurred among isolates of C. brevicomi either within or among sites. In contrast, E. sp. B exhibited highly variable responses to mid-range temperatures among sites and within some sites, and, unlike C. brevicomi, grew not at all or only very poorly at the highest and lowest temperatures tested. This variability affected both optimal temperature and maximum growth rate. The high variability in response to some temperatures among isolates of E. sp. B in some populations indicates that the ability to capture spatial and nutritional resources can vary greatly within this species which may have considerable impact on the outcome of both inter- and intra-specific competition among the fungi within trees and the short- and long-term dynamics of the fungi with the host beetle.
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Broadscale specificity in a bark beetle-fungal symbiosis: a spatio-temporal analysis of the mycangial fungi of the western pine beetle.
Microbial ecology, 2014Co-Authors: Ryan Bracewell, Diana L. SixAbstract:Whether and how mutualisms are maintained through ecological and evolutionary time is a seldom studied aspect of bark beetle–fungal symbioses. All bark beetles are associated with fungi and some species have evolved structures for transporting their symbiotic partners. However, the fungal assemblages and specificity in these symbioses are not well known. To determine the distribution of fungi associated with the mycangia of the western pine beetle (Dendroctonus brevicomis), we collected beetles from across the insect’s geographic range including multiple genetically distinct populations. Two fungi, Entomocorticium sp. B and Ceratocystiopsis brevicomi, were isolated from the mycangia of beetles from all locations. Repeated sampling at two sites in Montana found that Entomocorticium sp. B was the most prevalent fungus throughout the beetle’s flight season, and that females carrying that fungus were on average larger than females carrying C. brevicomi. We present evidence that throughout the flight season, over broad geographic distances, and among genetically distinct populations of beetle, the western pine beetle is associated with the same two species of fungi. In addition, we provide evidence that one fungal species is associated with larger adult beetles and therefore might provide greater benefit during beetle development. The importance and maintenance of this bark beetle–fungus interaction is discussed.
Brenda D Wingfield - One of the best experts on this subject based on the ideXlab platform.
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Draft genome sequences of Armillaria fuscipes, Ceratocystiopsis minuta, Ceratocystis adiposa, Endoconidiophora laricicola, E-polonica and Penicillium freii DAOMC 242723
IMA fungus, 2016Co-Authors: Brenda D Wingfield, Martin P. A. Coetzee, Z. Wilhelm De Beer, Tuan A. Duong, Fourie Joubert, Almuth Hammerbacher, Alistair R. Mctaggart, Kershney Naidoo, Jon Ambler, Hai D. T. NguyenAbstract:The genomes of Armillaria fuscipes, Ceratocystiopsis minuta, Ceratocystis adiposa, Endoconidiophora laricicola, E. polonica, and Penicillium freii DAOMC 242723 are presented in this genome announcement. These six genomes are from plant pathogens and otherwise economically important fungal species. The genome sizes range from 21 Mb in the case of Ceratocystiopsis minuta to 58 Mb for the basidiomycete Armillaria fuscipes. These genomes include the first reports of genomes for the genus Endoconidiophora. The availability of these genome data will provide opportunities to resolve longstanding questions regarding the taxonomy of species in these genera. In addition these genome sequences through comparative studies with closely related organisms will increase our understanding of how these pathogens cause disease.
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IMA Genome-F 6
IMA Fungus, 2016Co-Authors: Brenda D Wingfield, Jon M. Ambler, Martin P. A. Coetzee, Z. Wilhelm De Beer, Tuan A. Duong, Fourie Joubert, Almuth Hammerbacher, Alistair R. Mctaggart, Kershney Naidoo, Hai D. T. NguyenAbstract:The genomes of Armillaria fuscipes, Ceratocystiopsis minuta, Ceratocystis adiposa, Endoconidiophora laricicola, E. polonica , and Pénicillium freii DAOMC 242723 are presented in this genome announcement. These six genomes are from plant pathogens and otherwise economically important fungal species. The genome sizes range from 21 Mb in the case of Ceratocystiopsis minuta to 58 Mb for the basidiomycete Armillaria fuscipes. These genomes include the first reports of genomes for the genus Endoconidiophora. The availability of these genome data will provide opportunities to resolve longstanding questions regarding the taxonomy of species in these genera. In addition these genome sequences through comparative studies with closely related organisms will increase our understanding of how these pathogens cause disease.
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Multigene phylogenies define Ceratocystiopsis and Grosmannia distinct from Ophiostoma
2016Co-Authors: Renate D. Zipfel, Brenda D Wingfield, Wilhelm Z De Beer, Karin Jacobs, Michael J. WingfieldAbstract:Abstract: Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However
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STUDIES IN MYCOLOGY 55: 75–97. 2006. Multi-gene phylogenies define Ceratocystiopsis and Grosmannia distinct from
2013Co-Authors: Renate D. Zipfel, Brenda D Wingfield, Wilhelm Z De Beer, Karin Jacobs, Michael J. WingfieldAbstract:Abstract: Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However
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multi gene phylogenies define Ceratocystiopsis and grosmannia distinct from ophiostoma
Studies in Mycology, 2006Co-Authors: Renate Zipfel, Wilhelm Z De Beer, Brenda D Wingfield, Karin Jacobs, Michael J. WingfieldAbstract:Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However, these species are retained in Ophiostoma until further data for a larger number of species can be obtained to confirm monophyly of the apparent lineages.
Ryan Bracewell - One of the best experts on this subject based on the ideXlab platform.
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Cascading speciation among mutualists and antagonists in a tree-beetle-fungi interaction.
Proceedings. Biological sciences, 2018Co-Authors: Ryan Bracewell, Dan Vanderpool, Jeffrey M. Good, Diana L. SixAbstract:Cascading speciation is predicted to occur when multiple interacting species diverge in parallel as a result of divergence in one species promoting adaptive differentiation in other species. However, there are few examples where ecological interactions among taxa have been shown to result in speciation that cascades across multiple trophic levels. Here, we test for cascading speciation occurring among the western pine beetle ( Dendroctonus brevicomis ), its primary host tree ( Pinus ponderosa ), and the beetle9s fungal mutualists ( Ceratocystiopsis brevicomi and Entomocorticium sp. B). We assembled genomes for the beetle and a fungal symbiont and then generated reduced representation genomic data (RADseq) from range-wide samples of these three interacting species. Combined with published data for the host tree, we present clear evidence that the tree, the beetle, and the fungal symbionts are all genetically structured into at least two distinct groups that have strongly codiverged with geographical isolation. We then combine our genomic results with diverse population and laboratory-based data to show evidence for reproductive isolation at each level of the cascade and for coevolution of both antagonistic and mutualistic species interactions within this complex network.
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Temperature effects on growth of fungal symbionts of the western pine beetle, Dendroctonus brevicomis
Fungal Ecology, 2015Co-Authors: Joseph C. Dysthe, Ryan Bracewell, Diana L. SixAbstract:Abstract Differences in temperature ranges and optima among poikilothermic partners in symbioses can have profound effects on their interactions and stability. In this study, we investigated how the two mutualist mycangial fungi (Ceratocystiopsis brevicomi and Entomocorticium sp. B) associated with the western pine beetle, Dendroctonus brevicomis, respond to temperature in vitro. Little variability in growth rate at the various temperatures tested occurred among isolates of C. brevicomi either within or among sites. In contrast, E. sp. B exhibited highly variable responses to mid-range temperatures among sites and within some sites, and, unlike C. brevicomi, grew not at all or only very poorly at the highest and lowest temperatures tested. This variability affected both optimal temperature and maximum growth rate. The high variability in response to some temperatures among isolates of E. sp. B in some populations indicates that the ability to capture spatial and nutritional resources can vary greatly within this species which may have considerable impact on the outcome of both inter- and intra-specific competition among the fungi within trees and the short- and long-term dynamics of the fungi with the host beetle.
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Broadscale specificity in a bark beetle-fungal symbiosis: a spatio-temporal analysis of the mycangial fungi of the western pine beetle.
Microbial ecology, 2014Co-Authors: Ryan Bracewell, Diana L. SixAbstract:Whether and how mutualisms are maintained through ecological and evolutionary time is a seldom studied aspect of bark beetle–fungal symbioses. All bark beetles are associated with fungi and some species have evolved structures for transporting their symbiotic partners. However, the fungal assemblages and specificity in these symbioses are not well known. To determine the distribution of fungi associated with the mycangia of the western pine beetle (Dendroctonus brevicomis), we collected beetles from across the insect’s geographic range including multiple genetically distinct populations. Two fungi, Entomocorticium sp. B and Ceratocystiopsis brevicomi, were isolated from the mycangia of beetles from all locations. Repeated sampling at two sites in Montana found that Entomocorticium sp. B was the most prevalent fungus throughout the beetle’s flight season, and that females carrying that fungus were on average larger than females carrying C. brevicomi. We present evidence that throughout the flight season, over broad geographic distances, and among genetically distinct populations of beetle, the western pine beetle is associated with the same two species of fungi. In addition, we provide evidence that one fungal species is associated with larger adult beetles and therefore might provide greater benefit during beetle development. The importance and maintenance of this bark beetle–fungus interaction is discussed.
Kier D. Klepzig - One of the best experts on this subject based on the ideXlab platform.
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From Attack to Emergence: Interactions between southern pine beetle, mites, microbes and trees
2011Co-Authors: Kier D. Klepzig, Richard W. HofstetterAbstract:Bark beetles are among the most ecologically and economically influential organisms in forest ecosystems worldwide. These important organisms are consistently associated in complex symbioses with fungi. Despite this, little is known of the net impacts of the fungi on their vectors, and mites are often completely overlooked. In this chapter, we will describe interactions involving the southern pine beetle (SPB), among the most economically damaging of North American forest insects. We examine SPB interactions with mites, fungi, and other microbes, following the natural temporal progression from beetle attack to offspring emergence from trees. Associations with fungi are universal within bark beetles. Many beetle species possess specialized structures, termed mycangia, for the transport of fungi. The SPB consistently carries three main fungi and numerous mites into the trees it attacks. One fungus, Ophiostoma minus, is carried phoretically on the SPB exoskeleton and by phoretic mites. The mycangium of each female SPB may contain a pure culture of either Ceratocystiopsis ranaculosus or Entomocorticium sp. A. The mycangial fungi are, by definition, transferred in a specific fashion. The SPB possesses two types of gland cells associated with the mycangium. The role of these cells and their products remains unknown. Preliminary studies have observed yeast-like fungal spores in the mycangium and several surrounding tubes that presumably carry secreted chemicals from gland cells (or bacteria) to the mycangium. The degree to which there is selective activity of the glandular chemical secretions remains to be seen. While O. minus may play some role in tree killing, none of these three fungi are highly virulent in their pine hosts. All three fungi grow within the phloem, sporulating heavily in beetle tunnels within which the SPB larvae graze. Though their ecological roles are complex and context-dependent, these three fungi can be divided into an antagonist (O. minus) and two mutualists (both mycangial fungi, though Entomocorticium sp. A appears to be of greater benefit to the beetles than C. ranaculosus). Naturally, all three of the fungi compete for access to uncolonized pine phloem. The results of these competitions can have significant impacts on their beetle and mite hosts, and ultimately on the population dynamics of this destructive pest. From Attack to Emergence: Interactions between Southern Pine Beetle, Mites, Microbes,
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Competition between fungi associated with Sirex woodwasp and southern pine beetle
2009Co-Authors: Kier D. Klepzig, Bernard SlippersAbstract:The mutualistic symbiotic fungus of the invasive woodwasp Sirex noctilio is Amylostereum areolatum, a wood rotting fungus. Wood rotted by A. areolatum is fed upon by developing woodwasp larvae. The fungus itself serves as the food source for Deladenus siricidicola, a nematode that also parasitizes Sirex larvae. The resulting sterilization of adult woodwasps serves as the basis for biological control programs worldwide. Biological control of S. noctilio is achieved via the use of trap logs, colonized by nematodes feeding upon A. areolatum. Any interference with these linked life cycles may disrupt the biological control system and corresponding reductions in S. noctilio populations. We tested competitive interactions between A. areolatum and the southern pine beetle (SPB) fungal associates it may interact with if it becomes established in the U.S. South. Amylostereum areolatum (from South Africa), Ophiostoma minus, Ceratocystiopsis ranaculosus, and Entomocorticium sp. A (all from SPB in the U.S.) were pitted against one another on malt agar. The area colonized by each competing fungus was measured as an indicator of its ability to colonize (and defend) substrate. The primary phoretic associate of SPB was able to competitively exclude the mutualistic fungus of the Sirex woodwasp and vice versa. The success of SPB or Sirex associated fungi will thus likely depend upon order of arrival. The likely influences on success of Sirex biocontrol efforts may then include the following: 1. Timing of inoculation/ placement of trap trees —A. areolatum will need to be well established before exposure to insects vectoring stain fungi. 2. Variability within strains of A. areolatum and parasitic nematodes—Substantial variation exists in competitiveness of A. areolatum strains and in their compatibility with biocontrol nematodes. 3. Abundance of, and pressure from, indigenous pine colonizing beetles and their associated fungi—Seasonal and dynamical factors may influence pressure from competitors for log substrates.
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Analysis of cellulase and polyphenol oxidase production by southern pine beetle associated fungi
2008Co-Authors: Abduvali Valiev, Zumrut B. Ogel, Kier D. KlepzigAbstract:In this study, the production of extracellular enzymes by fungi associated with southern pine beetle was investigated for the first time. Cellulase and polyphenol oxidase production were analyzed for three beetle associated fungi. Only the mutualistic symbiont Entomocorticium sp. A was found to produce cellulases and polyphenol oxidase. In time course analyses of cellulase production in batch cultures, Entomocorticium sp. A showed maximum activity of 0.109 U/ml and 0.141 U/ml for total cellulase and endoglucanase activity respectively. Polyphenol oxidase production was simultaneous with fungal growth. Characterization of polyphenol oxidase by activity staining suggests that the enzyme is a tyrosinase/catechol oxidase. Enzyme assays in the presence of polyphenol oxidase inhibitors support the results of the activity staining. Keywords: Ceratocystiopsis, Entomocorticium, Ophiostoma, cellulase, tyrosinase/catechol oxidas
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Effects of available water on growth and competition of southern pine beetle associated fungi.
Mycological research, 2004Co-Authors: Kier D. Klepzig, J Flores-otero, R W Hofstetter, M P AyresAbstract:Competitive, interactions among bark beetle associated fungi are potentially influenced by abiotic factors. Water potential, in particular, undergoes marked changes over the course of beetle colonization of tree hosts. To investigate the impact of water potential on competition among three southern pine beetle associated fungi, Ophiostoma minus, Entomocorticium sp. A and Ceratocystiopsis ranaculosus, we utilized artificial media with water potentials of 0, -5, -10, and -20 MPa. Growth of all three fungi, when grown alone, decreased on media with lower water potentials. Growth rates of all three fungi were likewise reduced in competition experiments. At -5 to -10 MPa, C. ranaculosus (a fungus with beneficial effects toward southern pine beetle) was nearly equal in competitive ability to O. minus (a fungus with antagonistic effects towards southern pine beetle). This was not true on control media, nor at other water potentials tested. The range of water potentials used in our assays was similar to the range of water potentials we measured in loblolly pines within a southern pine beetle infestation. This study indicates that water potential may alter the outcome of competitive interactions among bark beetle-associated fungi in ways that favour bark beetle success.
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Biology, demography and community interactions of Tarsonemus (Acarina: tarsonemidae) mites phoretic on Dendroctonus frontalis (Coleoptera: Scolytidae)
Agricultural and Forest Entomology, 2000Co-Authors: María J. Lombardero, Kier D. Klepzig, John C. Moser, Matthew P. AyresAbstract:1- Dendroctonus frontalis, the southern pine beetle, is associated with a diverse community of fungi and mites that are phoretic on the adult beetles. Tarsonemus ips, T. kranzti and T. fusarii (Acarina: Tarsonemidae) may interact within this community in ways that link the population dynamics of D. frontalis, the mites and three dominant species of fungi. We explored species associations by comparing the dietary suitability of different fungi for Tarsonemus spp. 2 - All three mite species fed and reproduced at high rates when feeding on the bluestain fungus, Ophiostoma minus, which is an antagonist of D. frontalis larvae. 3 - Mites also had positive population growth rates when feeding upon Ceratocystiopsis ranaculosus, one of the mycangial fungi, but could barely reproduce when feeding upon Entomocorticium sp. A, the mycangial fungus that is most suitable for D. frontalis. 4 - During the time from colonization of a tree by D. frontalis adults until departure from the tree of their progeny (approximately equal to 40 d at 30 °C), mite pulations feeding upon O. minus can increase by factors of up to 209 (T. fusarii), 173 (T. ips) or 384 (T. krantzi). These high growth rates are allowed by rapid development (age of first reproduction = 8-9 d), high fecundity (approximately equal to 1 egg/d) and high longevity (> 28 d). 5 - Precocious mating increases the chance that females are mated prior to colonizing a new tree and arrhenotokous parthenogenesis permits reproduction by unmated females. 6 - Tarsonemus mites may introduce negative feedback into D. frontalis population dynamics by generating indirect interactions between D. frontalis and O. minus.