pathogen regulations

New legislation came into force earlier this week (20 April 2020), to address new plant health threats from three specific pathogens:

1. Xylella fastidiosa

 Xylella fastidiosa

Courtesy of Department for Environment, Food and Rural Affairs

Xylella fastidiosa is a bacterium yet to make it to the UK, but has caused well-documented damage to a wide range of plants throughout southern Europe.  Xylella fastidiosa has the potential to cause disease in a range of plants grown in the UK, which is why heightened measures are being introduced to prevent its spread to the UK.

Recent research suggests some plant species have very long asymptomatic periods, meaning plants infected with Xylella often show no symptoms for several years.  These are likely to pose a particular risk to UK biosecurity as per an updated pest risk analysis. The current EU measures to prevent the spread of Xylella fastidiosa do not address the risks identified in the pest risk analysis, and therefore the decision has been taken by Defra to introduce national measures. These are:

  • Prohibit the importation of Coffea and Polygala myrtifolia
  • Stronger import requirements for other high-risk hosts including Olive, Almond, Lavender and Rosemary.

2. Emerald Ash Borer

The emerald ash borer beetle

As the name suggests, the emerald ash borer is a non-native pest that has the potential to cause considerable damage to ash trees in the UK.  Like Xylella, the pest is not yet present in the UK. 

Due to the risk posed and the lack of information concerning the distribution of this pest, the UK is introducing measures which exceed current EU legislation and apply additional import requirements to countries within 100km of outbreak areas.  These requirements bring Ukraine (which has been confirmed as hosting the pest), Belarus and Kazakhstan into the regulated area.  The option currently within EU legislation, which allows regulated countries to remove bark and sapwood to a depth of 2.5cm and continue exporting ash wood has also been removed by the UK, due to the risk – highlighted by the US and Canada – of this option not being administered or enforced reliably.   

3. Canker Stain of Plane

Canker stain of plane

Courtesy of London Tree Officers Association

Ceratocystis platani is an aggressive fungal pathogen that attacks plane trees by entering through wounds and causing canker stain disease and tree death.  The UK was previously designated as a protected zone for this pest, however, protected zone designations have since been revoked, meaning it is now possible to move Platanus trees from sites within infected areas, which presents a risk to the UK.  Therefore, the UK is revering to Protected Zone requirements, meaning plants of Platanus imported to the UK for planting from Albania, Switzerland, Turkey, US and EU-27 must have been grown throughout their life in a pest free area of EU protected zone.   

Full details of the measures are detailed in the document here