For pests currently absent from the UK, risk of introduction is assessed. For pests already present in the UK risk of spread to maximum extent is assessed. Some other scenarios exist.
The specific pathway(s) that were considered when rating entry of a pest to the UK. These were the pathways considered to present the highest risk of entry.
All pathways the pest may enter or spread around the UK on.
What risks would be without any co-ordinated action. Ratings do take into account how normal grower practises (such as pesticide treatments) would affect risks.
See Guidance Document for more Information
For "Pest is Introduced" the lowest value of Entry or Establishment, as both are required for a successful introduction. For "Pest Spreads to Maximum Extent" this is an expert judgement on the likelihood of this occurrence.
The Likelihood of movement of the pest into the UK on a pathway and transfer of that pest to a suitable host.
The likelihood of the pest surviving and perpetuating in the UK for the foreseeable future after it has entered.
The rate at which a pest can expand, by natural dispersal only, within an area.
The highest value from economic, environmental or social impacts.
The predicted economic impacts of the pest in the UK. This includes direct effects on yield, quality and possible indirect effects such as trade implications.
The proportion of the environmental value of the plant which is likely to be lost through the introduction of the pest.
The predicted social impacts of a pest in the UK, including effects on tourism, amenities and animal and human health.
The value of the hosts or industries at risk from this pest in the UK.
The likelihood multiplied by the impact, which shows the risk to the sector.
Likelihood x Impact x Value at Risk.
All mitigations currently in place for a pest.
Regulated non quarantine pest
Risks rated to take into account the effects of co-ordinated actions that are in place such as EU regulation or industry accreditation schemes.
The hosts or industries in the UK that were considered when rating the pest as being at risk.
Ornamental and fruit trees (Morus and Prunus)
The main regulation which applies: The Plant Health (Phytosanitary Conditions) (Amendment) (EU Exit) Regulations 2020Regulated quarantine pest; regulated non-quarantine pest; regulated pest free area pest: defined in the above legislation.Regulated by emergency measures: individual pieces of legislation to regulate certain pests.General plant health powers apply: plant pests not specifically listed in legislation, but which have been assessed as harmful. Statutory action would be taken against findings, using general powers available in plant health legislation.EPPO listings are advisory categories only, and do not have a legal basis:A1 list is for pests which are not present in any part of the EPPO region.A2 list is for pests which occur in at least one part of the EPPO region.Alert list is an early warning system for emerging pests.We recommend that you consult the original source to confirm the legal status of any given pest.
A summary of priorities for action.
Statutory action against interceptions.
Scale insect which in favourable conditions may kill trees. There have been a number of findings in the UK but some uncertainty about whether the pest is established.
Ticks indicate key sources of uncertainty for this pest. A cross indicates that there is less uncertainty associated with that aspect of the pest’s biology. A cross does not indicate there is full knowledge, merely that the uncertainties are unlikely to influence the rating (score).
Potential outdoor distribution in UK climate