title: Metschnikowia cf. typographi and other pathogens from the bark beetle Ips sexdentatus - Prevalence, histological and ultrastructural evidence, and molecular characterization.
abstract: Ips sexdentatus (six-spined engraver beetle) from Austria and Poland were dissected and examined for the presence of pathogens. Specimens collected in Austria were found to contain the ascomycetous fungus Metschnikowia cf. typographi. Infection rates ranged from 3.6% to 26.8% at different collection sites. M. cf. typographi infected midguts were investigated by histological, ultrastructural and molecular techniques. Extraordinary ultrastructural details are shown, such as ascospores with bilateral flattened flanks resembling alar rims at both sides of their attenuating tube-like ends. These have not yet been described in other yeast species. Molecular investigations showed a close phylogenetic relationship to the fungi Metschnikowia agaves and Candida wancherniae. Presence of the entomopathogenic fungus Beauveria bassiana found in Austria was confirmed both morphologically and molecularly. The eugregarine Gregarina typographi was diagnosed most frequently. Infection rates of all I. sexdentatus specimens ranged from 21.4% to 71.9% in Austria and 54.1% to 68.8% in Poland. Other entomopathogenic protists, bacteria, or viruses were not detected.
authors.affiliation: Julius Kühn-Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Biological Control, Heinrichstrasse 243, 64287 Darmstadt, Germany. Electronic address: regina.kleespies@julius-kuehn.de.
authors.forename: Regina G
authors.initials: RG
authors.lastname: Kleespies
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea. Electronic address: ywlim@snu.ac.kr.
authors.forename: Young Woon
authors.initials: YW
authors.lastname: Lim
authors.affiliation: Siedlce University of Natural Sciences and Humanities, Department of Plant Protection and Breeding, Prusa 14, 08-110 Siedlce, Poland. Electronic address: tkaczuk@uph.edu.pl.
authors.forename: Cezary
authors.initials: C
authors.lastname: Tkaczuk
authors.affiliation: Biological and Chemical Research Center, Faculty of Biology, Al. Żwirki i Wigury 101, Warsaw, Poland. Electronic address: martawrzosek@gmail.com.
authors.forename: Marta
authors.initials: M
authors.lastname: Wrzosek
authors.affiliation: University of Copenhagen, Department of Plant and Environmental Sciences, Denmark; University of Natural Resources and Life Sciences, Vienna, Gregor Mendel Str. 33, A-1180 Vienna, Austria. Electronic address: b.steinwender@t-online.de.
authors.forename: Bernhardt M
authors.initials: BM
authors.lastname: Steinwender
authors.affiliation: University of Natural Resources and Life Sciences, Vienna, Gregor Mendel Str. 33, A-1180 Vienna, Austria. Electronic address: rudolf.wegensteiner@boku.ac.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Wegensteiner
mesh_terms: D000818:Animals; D001317:Austria; D001517:Coleoptera / Q000382:microbiology*; D005800:Genes, Fungal; D055163:Metschnikowia / Q000235:genetics / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D011044:Poland; D016133:Polymerase Chain Reaction
keywords: Entomopathogenic fungus; Molecular characters; Six-spined engraver beetle; Transmission electron microscopy; Ultrastructure; Yeast