• Pest is introduced

• Plants for planting (except seeds bulbs and tubers)

• Plants for planting (except seeds bulbs and tubers)
• Seeds

× Likelihood 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. See Guidance Document for more Information Close Likelihood [1 - 5]				4
× Spread The rate at which a pest can expand, by natural dispersal only, within an area. See Guidance Document for more Information Close Spread [1 - 5]		2
× Impact The highest value from economic, environmental or social impacts. See Guidance Document for more Information Close Impact [1 - 5]		2
× Value at Risk The value of the hosts or industries at risk from this pest in the UK. See Guidance Document for more Information Close Value at Risk [1 - 5]		2
× Likelihood x Impact The likelihood multiplied by the impact, which shows the risk to the sector. See Guidance Document for more Information Close Likelihood x Impact [1 - 25]	8
× UK Relative Risk Rating Likelihood x Impact x Value at Risk. See Guidance Document for more Information Close UK Relative Risk Rating [1 - 125]	16

Key mitigation for pest

Regulation

Surveillance

Industry Scheme

Contingency Plan

Awareness

Research

× Likelihood 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. See Guidance Document for more Information Close Likelihood [1 - 5]				4
× Spread The rate at which a pest can expand, by natural dispersal only, within an area. See Guidance Document for more Information Close Spread [1 - 5]		2
× Impact The highest value from economic, environmental or social impacts. See Guidance Document for more Information Close Impact [1 - 5]		2
× Value at Risk The value of the hosts or industries at risk from this pest in the UK. See Guidance Document for more Information Close Value at Risk [1 - 5]		2
× Likelihood x Impact The likelihood multiplied by the impact, which shows the risk to the sector. See Guidance Document for more Information Close Likelihood x Impact [1 - 25]	8
× UK Relative Risk Rating Likelihood x Impact x Value at Risk. See Guidance Document for more Information Close UK Relative Risk Rating [1 - 125]	16

Regulation

Deregulation

Management By Industry

Targeted Survey

PRA

Contingency Plan

Publicity

Research

Country / Territory			Status			Notes
Europe
	United Kingdom		Absent
	Netherlands		Present
	Belgium		Present
	Germany		Present
	Italy		Present
North America
	United States		Present

• Bacterium

Hydrangea production and garden centres

• Hydrangea arborescens ssp. arborescens L.
• Hydrangea quercifolia Bartr.

• Both protected crops and outdoor production

• N/A

PRA Availability

PRA not available

Not currently listed

Action

No statutory action in Great Britain.

General Comments

Bacterial pathogen of Hydrangeae causing leaf spots and stem rots of hosts. Many aspects of the pathogen are uncertain, in particular due to it undergoing recent taxonomic changes. It is unlikely to have severe impacts in the UK due to current industry management measures.

Key uncertainty for pest

The pathogen has only recently emerged and been named as a separate species. There is therefore very little data on the species specifically and as such much of the information is based on the effects of the closely related species X. hortorum and its pathovars.

Climate

Current distribution

Hosts

Impact

Pathways

Regulation

Taxonomy

UK distribution