page_title: Dutch elm disease
section_title: Overview
hierarchical_section_title: Dutch elm disease / Overview
caption_attribution_description: A large English Elm infected with Dutch Elm Disease at West Point, NY June 2010
context_page_description: Dutch elm disease is caused by a member of the sac fungi affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was 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 affects species in the genera Ulmus and Zelkova; therefore it is not specific to the Dutch elm hybrid.
context_section_description: The causative agents of DED are ascomycete microfungi. 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.
  DED is spread in North America by three species of bark beetles (Family: Curculionidae, Subfamily: Scolytinae):
  The native elm bark beetle, Hylurgopinus rufipes.
  The smaller 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.
  Other reported DED vectors include Scolytus sulcifrons, S. pygmaeus, S. laevis, Pteleobius vittatus and Р. kraatzi. Other elm bark beetle species are also likely vectors.
caption: An infected English elm at West Point, NY, July 2010
exif: {"Image ImageDescription": "", "Image Make": "SONY", "Image Model": "DSC-H50", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "QuickTime 7.6.6", "Image DateTime": "2010:07:05 14:17:03", "Image HostComputer": "Mac OS X 10.6.4", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "284", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "9680", "Thumbnail JPEGInterchangeFormatLength": "6218", "Thumbnail YCbCrPositioning": "Centered", "EXIF ExposureTime": "1/320", "EXIF FNumber": "28/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2010:07:03 12:27:26", "EXIF DateTimeDigitized": "2010:07:03 12:27:26", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "3", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "23/8", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, auto mode", "EXIF FocalLength": "26/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3456", "EXIF ExifImageLength": "2592", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal"}