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Pine wood nematode (Bursaphelenchus xylophilus)

Pinewood nematodes in a water droplet












Pine wood nematode (PWN - Bursaphelenchus xylophilus), is regarded as a serious threat to European forests. This is particularly so since its establishment in Portugal and the fact that, even with the application of stringent measures, the pest has continued to spread and kill pine trees in that country.

Infestation of pine trees by PWN causes a condition called pine wilt or pine wilt disease, and is often fatal to the tree.

The basis for classifying PWN as a highly significant threat is well documented. It has a track record of killing pine trees in:

  • Japan (where tree deaths were noted in the 19th century, but the nematode as a causal agent was only confirmed in the late 1960s);
  • China (from 1982);
  • Korea (from 1988);
  • Taiwan (from 1985);
  • Portugal (continental Portugal in 1999 and Madeira in 2009); and
  • Spain (2008) - a single infested tree.

There have been extensive tree deaths in all countries where wilt expression has been recorded (leading to the term 'pine wilt disease').

Our contingency planwill ensure that government agencies make a rapid response to any outbreak of the pest in Great Britain.

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Last updated: 13th February 2018