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Jørgen Eilenberg - One of the best experts on this subject based on the ideXlab platform.

  • 3 authors, including:
    2016
    Co-Authors: Jørgen Eilenberg, Lene Thomsen José Bresciani
    Abstract:

    Formation and germination of resting spores from different strains from the Entomophthora muscae complex produced in Musca domestica

  • differential divergences of obligately insect pathogenic Entomophthora species from fly and aphid hosts
    Fems Microbiology Letters, 2009
    Co-Authors: Annette Bruun Jensen, Jørgen Eilenberg, Claudia Lopez C Lastra
    Abstract:

    Three DNA regions (ITS 1, LSU rRNA and GPD) of isolates from the insect-pathogenic fungus genus Entomophthora originating from different fly (Diptera) and aphid (Hemiptera) host taxa were sequenced. The results documented a large genetic diversity among the fly-pathogenic Entomophthora and only minor differences among aphid-pathogenic Entomophthora. The evolutionary time of divergence of the fly and the aphid host taxa included cannot account for this difference. The host-driven divergence of Entomophthora, therefore, has been much greater in flies than in aphids. Host-range differences or a recent host shift to aphid are possible explanations.

  • Differential divergences of obligately insect‐pathogenic Entomophthora species from fly and aphid hosts
    FEMS microbiology letters, 2009
    Co-Authors: Annette Bruun Jensen, Jørgen Eilenberg, Claudia C. López Lastra
    Abstract:

    Three DNA regions (ITS 1, LSU rRNA and GPD) of isolates from the insect-pathogenic fungus genus Entomophthora originating from different fly (Diptera) and aphid (Hemiptera) host taxa were sequenced. The results documented a large genetic diversity among the fly-pathogenic Entomophthora and only minor differences among aphid-pathogenic Entomophthora. The evolutionary time of divergence of the fly and the aphid host taxa included cannot account for this difference. The host-driven divergence of Entomophthora, therefore, has been much greater in flies than in aphids. Host-range differences or a recent host shift to aphid are possible explanations.

  • value of host range morphological and genetic characteristics within the Entomophthora muscae species complex
    Fungal Biology, 2006
    Co-Authors: Annette Bruun Jensen, Lene Thomsen, Jørgen Eilenberg
    Abstract:

    Entomopthora muscae sensu lato is a complex of morphologically similar fungal species pathogenic to evolutionarily advanced flies (Cyclorrhapha). To reach an operational species definition and recognition of species within this complex, the values of host range, morphological and genetic characteristics are reconsidered. Within the E. muscae species complex morphological and nuclear characteristics of the primary conidia are taxonomically important. In this study we compared the dimensions and nuclear numbers of the primary conidia of isolates from their original (natural) hosts and after being transferred to alternative hosts (cross-transmission) in order to check the stability of these characteristics. The conidial characteristics change substantially when produced in alternative host species, but their overall range in variability still fit within the traditional morphological species circumscriptions. The phylogenetic analyses of the ITS II and LSU rRNA gene sequences, revealed three distinct lineages within the complex: E. schizophorae, E. muscae and E. syrphi. Within each of these lineages sequence divergence was seen between isolates originating from different host species. Our studies on the physiological host range showed that several isolates were able to infect alternative dipteran species. Musca domestica was a particularly good receptor. The ecological host range of any individual isolate seems, however, to be limited to one host species evidenced by the occurrence of distinct genotypes within each natural infected host species shown by RAPD. The high host specificity of these fungi emphasizes the importance of identifying the host taxon at species level in the recognition of Entomophthora species. We recommend that morphological characteristics of fungal structures and host taxon, together with molecular data, serve as criteria for species determination in future studies on members of the E. muscae complex.

  • Entomophthora ferdinandii (Zygomycetes: Entomophthorales) causing natural infections of Musca domestica (Diptera: Muscidae) in Argentina.
    Mycopathologia, 2006
    Co-Authors: Claudia C. López Lastra, Jørgen Eilenberg, Augusto Siri, J J Garcia, Richard A. Humber
    Abstract:

    The identity and activity of an entomopathogenic fungus belonging to the Entomophthora muscae species complex and infecting Musca domestica in poultry houses from La Plata, Argentina, is reported. Entomophthora caused natural infections between September 2001 and September 2003. Primary conidia of this fungus were on average 29.5 ± 1.2 × 23.4 ± 2.4 µm and contained, on average, 10.5 ± 0.1 nuclei (range: 7–15) with an average diameter of 4.8 ± 0.1 µm. This fungus is identified as E. ferdinandii Keller (this specific epithet includes a nomenclaturally required spelling correction); this is a first record of E. ferdinandii in South America and of any member of the E. muscae species complex from flies in Argentina.

Annette Bruun Jensen - One of the best experts on this subject based on the ideXlab platform.

  • differential divergences of obligately insect pathogenic Entomophthora species from fly and aphid hosts
    Fems Microbiology Letters, 2009
    Co-Authors: Annette Bruun Jensen, Jørgen Eilenberg, Claudia Lopez C Lastra
    Abstract:

    Three DNA regions (ITS 1, LSU rRNA and GPD) of isolates from the insect-pathogenic fungus genus Entomophthora originating from different fly (Diptera) and aphid (Hemiptera) host taxa were sequenced. The results documented a large genetic diversity among the fly-pathogenic Entomophthora and only minor differences among aphid-pathogenic Entomophthora. The evolutionary time of divergence of the fly and the aphid host taxa included cannot account for this difference. The host-driven divergence of Entomophthora, therefore, has been much greater in flies than in aphids. Host-range differences or a recent host shift to aphid are possible explanations.

  • Differential divergences of obligately insect‐pathogenic Entomophthora species from fly and aphid hosts
    FEMS microbiology letters, 2009
    Co-Authors: Annette Bruun Jensen, Jørgen Eilenberg, Claudia C. López Lastra
    Abstract:

    Three DNA regions (ITS 1, LSU rRNA and GPD) of isolates from the insect-pathogenic fungus genus Entomophthora originating from different fly (Diptera) and aphid (Hemiptera) host taxa were sequenced. The results documented a large genetic diversity among the fly-pathogenic Entomophthora and only minor differences among aphid-pathogenic Entomophthora. The evolutionary time of divergence of the fly and the aphid host taxa included cannot account for this difference. The host-driven divergence of Entomophthora, therefore, has been much greater in flies than in aphids. Host-range differences or a recent host shift to aphid are possible explanations.

  • value of host range morphological and genetic characteristics within the Entomophthora muscae species complex
    Fungal Biology, 2006
    Co-Authors: Annette Bruun Jensen, Lene Thomsen, Jørgen Eilenberg
    Abstract:

    Entomopthora muscae sensu lato is a complex of morphologically similar fungal species pathogenic to evolutionarily advanced flies (Cyclorrhapha). To reach an operational species definition and recognition of species within this complex, the values of host range, morphological and genetic characteristics are reconsidered. Within the E. muscae species complex morphological and nuclear characteristics of the primary conidia are taxonomically important. In this study we compared the dimensions and nuclear numbers of the primary conidia of isolates from their original (natural) hosts and after being transferred to alternative hosts (cross-transmission) in order to check the stability of these characteristics. The conidial characteristics change substantially when produced in alternative host species, but their overall range in variability still fit within the traditional morphological species circumscriptions. The phylogenetic analyses of the ITS II and LSU rRNA gene sequences, revealed three distinct lineages within the complex: E. schizophorae, E. muscae and E. syrphi. Within each of these lineages sequence divergence was seen between isolates originating from different host species. Our studies on the physiological host range showed that several isolates were able to infect alternative dipteran species. Musca domestica was a particularly good receptor. The ecological host range of any individual isolate seems, however, to be limited to one host species evidenced by the occurrence of distinct genotypes within each natural infected host species shown by RAPD. The high host specificity of these fungi emphasizes the importance of identifying the host taxon at species level in the recognition of Entomophthora species. We recommend that morphological characteristics of fungal structures and host taxon, together with molecular data, serve as criteria for species determination in future studies on members of the E. muscae complex.

  • Isolation and in vitro cultivation of the aphid pathogenic fungus Entomophthora planchoniana.
    Canadian journal of microbiology, 2001
    Co-Authors: Florian M. Freimoser, Annette Bruun Jensen, Urs Tuor, Markus Aebi, Jørgen Eilenberg
    Abstract:

    Entomophthora planchoniana is an important fungal pathogen of aphids. Although Entomophthora chromaphidis has been considered a synonym for E. planchoniana, the two species are now separated, and E. planchoniana is reported not to grow in vitro. In this paper, we describe for the first time the isolation and cultivation of this species. Entomophthora planchoniana was isolated from a population of Ovatus crataegarius (Homoptera, Aphididae), which was infected by E. planchoniana only. The isolates did not sporulate, but the sequence of the small subunit rDNA and the restriction fragment length polymorphism patterns of the first part of the large subunit rDNA and the ITS II region confirm that the isolates were E. planchoniana. The isolated fungus grew in a medium consisting of Grace's insect cell culture medium supplemented with lactalbumin hydrolysate, yeastolate, and 10% fetal bovine serum or in GLEN medium with 10% fetal bovine serum. Vegetative cells of E. planchoniana were long and club-shaped and did ...

  • genetic variation within the insect pathogenic genus Entomophthora focusing on the e muscae complex using pcr rflp of the its ii and the lsu rdna
    Fungal Biology, 2001
    Co-Authors: Annette Bruun Jensen, Jørgen Eilenberg
    Abstract:

    The ITS II and the first part of the LSU rDNA were amplified from 26 isolates within the genus Entomophthora. The specificity of the primers allowed the use of both in vivo and in vitro material. Size polymorphism and long amplification of the ITS II regions, ranging from 1200 to 2000 bp, were observed. The PCR-products were cut with eight different restriction endonucleases and analysed by UPGMA, one analysis from each of the two regions. Conidial morphology was of predictive value for the overall taxonomy of the genus Entomophthora, as the genus clustered together in the analysis of the LSU rDNA. In both analyses the E. muscae complex clustered into three different clades, which support the validity of E. schizophorae and E. syrphi as separate species. Considerable variation was detected in the E. muscae clade, but it could not be grouped by host, geographic origin or conidial morphology, though the E. muscae s. sir. isolates in both analyses grouped together. One isolate with E. muscae-like conidia found on Hymenoptera clustered out within the E. muscae clade, widening the host range for E. muscae significantly.

Lene Thomsen - One of the best experts on this subject based on the ideXlab platform.

  • value of host range morphological and genetic characteristics within the Entomophthora muscae species complex
    Fungal Biology, 2006
    Co-Authors: Annette Bruun Jensen, Lene Thomsen, Jørgen Eilenberg
    Abstract:

    Entomopthora muscae sensu lato is a complex of morphologically similar fungal species pathogenic to evolutionarily advanced flies (Cyclorrhapha). To reach an operational species definition and recognition of species within this complex, the values of host range, morphological and genetic characteristics are reconsidered. Within the E. muscae species complex morphological and nuclear characteristics of the primary conidia are taxonomically important. In this study we compared the dimensions and nuclear numbers of the primary conidia of isolates from their original (natural) hosts and after being transferred to alternative hosts (cross-transmission) in order to check the stability of these characteristics. The conidial characteristics change substantially when produced in alternative host species, but their overall range in variability still fit within the traditional morphological species circumscriptions. The phylogenetic analyses of the ITS II and LSU rRNA gene sequences, revealed three distinct lineages within the complex: E. schizophorae, E. muscae and E. syrphi. Within each of these lineages sequence divergence was seen between isolates originating from different host species. Our studies on the physiological host range showed that several isolates were able to infect alternative dipteran species. Musca domestica was a particularly good receptor. The ecological host range of any individual isolate seems, however, to be limited to one host species evidenced by the occurrence of distinct genotypes within each natural infected host species shown by RAPD. The high host specificity of these fungi emphasizes the importance of identifying the host taxon at species level in the recognition of Entomophthora species. We recommend that morphological characteristics of fungal structures and host taxon, together with molecular data, serve as criteria for species determination in future studies on members of the E. muscae complex.

  • Formation and germination of resting spores from different strains from the Entomophthora muscae complex produced in Musca domestica
    Canadian Journal of Botany, 2001
    Co-Authors: Lene Thomsen, José Bresciani, Jørgen Eilenberg
    Abstract:

    Three species within the Entomophthora muscae (Cohn) Fresenius complex (Entomophthora schizophorae Keller & Wilding, E. muscae s.str., and E. muscae "group B") were investigated for resting spore formation in vivo in the house fly (Musca domestica L.). Resting spores of E. muscae group B were experimentally induced from August to the beginning of February, while no resting spores were ever observed in E. schizophorae infected M. domestica or in flies infected by E. muscae s.str. originating from M. domestica. When newly dead fly cadavers containing E. muscae group B resting spores were kept moist, cystidia emerged from the abdomen; this is the first report of cystidia in the genus Entomophthora. Resting spore production was significantly affected by both temperature and E. muscae group B strain. More infected flies formed resting spores when kept 1 week at 10°C compared with constant exposure at 22°C, but the tendency of the different E. muscae group B strains to form resting spores persisted with shiftin...

Růžena Krejzová - One of the best experts on this subject based on the ideXlab platform.

  • Germination process in resting spores of some Entomophthora species and pathogenicity of spore material for lepidopterous larvae
    Zeitschrift für Angewandte Entomologie, 2009
    Co-Authors: Růžena Krejzová
    Abstract:

    The process of preparation to germination, germination of resting spores, and formation of hyphae, hyphal bodies, primary and secondary germ conidia and germ microconidia was studied in E. thaxteriana, E. virulenta and E. destruens. The studied species and strains of the genus Entomophthora showed a low germination rate. The percentage of mortality obtained in butterfly larvae while using a dry and resuspended spore material previously left to germinate was much higher than if resting spores from a fresh submersed culture were applied. Of great significance was the preliminary germination of the material, since it led to the formation of numerous conidia which are able to penetrate through the body surface of the host and to produce the infection. The infection material obtained in this way showed a low host-specificity and the species and strains isolated from aphids and mosquitoes could be successfully applied for butterfly larvae. Zusammenfassung Uber den Keimungsprozes bei Dauersporen einiger Entomophthora-Arten und die Pathogenitat des Sporenmaterials fur Lepidopteren-Larven Der Prozes der Keimungsvorbereitung, Keimung der Dauersporen, Formation der Hyphen, Hyphenkorper, Primrar- und Sekundar-Konidien sowie Mikrokonidien wurde bei den 3 Entomophthora-Arten E. thaxteriana, E. virulenta und E. destruens untersucht. Die Arten und Stamme zeigten eine niedrige Keimungsrate. Der Prozentsatz der Mortalitat bei Schmetterlingsraupen nach Anwendung eines trockenen und wieder aktivierten Sporenmaterials war erheblich hoher als bei Anwendung von Dauersporen einer frischen Submerskultur. Von groser Bedeutung war die vorbereitende Keimung des Materials, da sie zur Bildung zahlreicher Konidien fuhrte, welche imstande sind, in die Korperoberflache des Wirtes einzudringen und die Infektion herbeizufuhren. Das auf diese Weise gewonnene Infektionsmaterial zeigte eine nur geringe Wirts-Spezifitat. Die aus Blattlausen und Stechmucken isolierten Stamme konnten erfolgreich gegen Lepidopteren-Larven angewandt werden.

Huger A. M. - One of the best experts on this subject based on the ideXlab platform.

  • Neuere Befunde über Conidiobolus tenthredinis (Zygomycetes, Entomophthoraceae), ein Pathogen von Blattwespenlarven (Tenthredinidae)
    Nachrichtenblatt des Deutschen Pflanzenschutzdienstes, 2018
    Co-Authors: Zimmermann G., Huger A. M.
    Abstract:

    Als Erreger einer Mykose bei Blattwespenlarven, wahrscheinlich der Gattung Dolerus, wurde der Pilz Conidiobolus (= Entomophthora) tenthredinis nachgewiesen. Neben den Fundangaben werden die Krankheitssymptome und -merkmale der Wirtstiere, die Morphologie der Pilzstadien sowie die histopathologischen Befunde anhand von gefärbten Schnittpräparaten geschildert und dargestellt. Für die Art besonders charakteristisch sind die im Mittel 47,5 x 36,5 µm großen, vielkernigen, birnenförmigen Konidien, die stark pleomorphen Hyphenkörper und die 46-60 µm großen Dauersporen. Die systematische Einordnung von C. tenthredinis wird aufgrund der Kernzahl in den Konidien (etwa 30-50) und des Kerntyps (entomophthoroid) diskutiert. Einige Bemerkungen zum Auftreten dieser Art werden angeführt. New data on Conidiobolus tenthredinis (Zygomycetes, Entomophthoraceae), a pathogen of sawfly larvae (Tenthredinidae) The fungus Conidiobolus (= Entomophthora) tenthredinis was found as a pathogen of sawfly larvae, probably of the genus Dolerus. Besides ecological observations, signs and symptoms of the disease, morphological characteristics of the fungus, and histopathological findings from stained serial sections are described and presented. Typical features of the species are: the pear-shaped, multinucleate conidia with a mean size of 47.5 X 36.5 µm, the pleomorphic hyphal bodies, and the resting spores with diameters between 46-60 µm. The taxonomic classification of C. tenthredinis is discussed with respect to conidial nuclear number (ca. 30-50) and nuclear type (entomophthoroid). Remarks on the occurrence of this fungus are added