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UK Risk Register Details for Orgyia leucostigma

This record was last updated on 11/07/2024

Common Names

  • White-marked Tussock Moth

Scenario and Pathways

Scenario for Risk Register

  • show / hide
  • Pest is introduced

Pathway Assessed for Entry to UK

  • show / hide
  • Hitchhiking

Common Pathways

  • show / hide
  • Plants for planting (except seeds bulbs and tubers)
  • Cut flowers or branches
  • Bark
  • Wood packaging material
  • Agricultural machinery
  • Hitchhiking
  • Firewood
  • packing cases
  • Roundwood of oak with bark present
  • vehicles/containers
  • Woodchip

Risk Ratings and Current Mitigations

Unmitigated Risks

Likelihood [1 - 5] 3
Spread [1 - 5] 2
Impact [1 - 5] 3
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 9
UK Relative Risk Rating [1 - 125] 45

Current Mitigations

  • show / hide

Key mitigation for pest

The prohibition of planting material and the restrictions on high-risk hosts as well as wood/wood material from USA and Canada.



Industry Scheme

Contingency Plan



Mitigated Risks

Likelihood [1 - 5] 3
Spread [1 - 5] 2
Impact [1 - 5] 3
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 9
UK Relative Risk Rating [1 - 125] 45

Proposed Actions

Proposed Actions



Management By Industry

Targeted Survey


Contingency Plan



Distribution and Pest Details


Country / Territory Status Notes
North America
Canada Present Manitoba, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec
United States Present Alabama, Arkansas, Colorado, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin
Central America
Cuba Present

Type of Pest

  • Insect (Lepidoptera)

Host or Industry at Risk

  • show / hide

Broadleaved and coniferous trees

Major Hosts

  • Abies balsamea (L.) Mill.
  • Acer L.
  • Aesculus hippocastanum L.
  • Albizia julibrissin Durazz.
  • Alnus Mill.
  • Betula L.
  • Catalpa Scop.
  • Cercis L.
  • Fagus L.
  • Fragaria L.
  • Juglans nigra L.
  • Larix Mill.
  • Malus Mill.
  • Malus domestica Borkhausen
  • Picea A.Dietr.
  • Pinus strobus L.
  • Platanus L.
  • Populus L.
  • Prunus L.
  • Prunus domestica ssp. domestica L.
  • Pyracantha coccinea M.J.Roem.
  • Pyrus communis L.
  • Quercus L.
  • Rosa L.
  • Rubus L.
  • Salix L.
  • Tamarix gallica L.
  • Tilia americana L.
  • Tsuga Carr.
  • Ulmus L.
  • Vaccinium L.
  • Zea L.

Threats to Protected Cultivation

  • N/A

Forest Tree Pests and Pathogens

  • Broadleaved & Coniferous

Further Information

PRA Availability


Regulation and EPPO listing

  • show / hide

EPPO A1 (2021) Not listed in UK/GB

Actions Indicated

  • show / hide


Statutory action in Great Britain.

General Comments

Polyphagous moth pest from North America which could be damaging to broadleaf, coniferous, fruit, and ornamental trees and some crop species if introduced to the UK, as well as having human health impacts. The main pathway is likely to be on goods (including non-plant material) imported from North America.

Further Information


  • show / hide

Key uncertainty for pest

How much human facilitated movement would add to the spread of this pest.


Current distribution






UK distribution

Risk Records for this Pest