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Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native populations of elms that did not have resistance to the disease. It has also reached New Zealand. The name "Dutch elm disease" refers to its identification in 1921 and later in the Netherlands by Dutch phytopathologists Bea Schwarz and Christine Buisman who both worked with Professor Johanna Westerdijk. The disease is not specific to the Dutch elm hybrid.〔(【引用サイトリンク】publisher=UK Forestry Commission )〕〔(【引用サイトリンク】work=Plant Sciences )〕 == Overview == The causative agents of DED are ascomycete microfungi.〔(Ascomycetes: Phylum Ascomycota ), ''Biology of Plants, Seventh Edition'', W. H. Freeman and Company, 2005.〕 Three species are now recognized: *''Ophiostoma ulmi'', which afflicted Europe from 1910, reaching North America on imported timber in 1928. *''Ophiostoma himal-ulmi'', a species endemic to the western Himalaya. *''Ophiostoma novo-ulmi'', an extremely virulent species from Japan which was first described in Europe and North America in the 1940s and has devastated elms in both continents since the late 1960s.〔Johnson, O. (2011). ''Champion Trees of Britain and Ireland''. Royal Botanic Gardens, Kew. ISBN 978-1842464526〕 DED is spread in North America by three species of bark beetles (Family: Curculionidae, Subfamily: Scolytinae): *The native elm bark beetle, ''Hylurgopinus rufipes''. *The European elm bark beetle, ''Scolytus multistriatus''. *The banded elm bark beetle, ''Scolytus schevyrewi''. In Europe, while ''S. multistriatus'' still acts as a vector for infection, it is much less effective than the large elm bark beetle, ''S. scolytus''. ''H. rufipes'' can be a vector for the disease, but is inefficient compared to the other vectors. ''S. schevyrewi'' was found in 2003 in Colorado and Utah. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dutch elm disease」の詳細全文を読む スポンサード リンク
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