UK Risk Register Details for Thaumetopoea processionea

This record was last updated on 24/04/2020

Common Names

  • Oak processionary caterpillar
  • Oak processionary moth

Scenario and Pathways

Scenario for Risk Register

  • show / hide
  • Pest spreads to maximum extent

Pathway Assessed for Entry to UK

  • show / hide

Common Pathways

  • show / hide
This section is currently being developed as part of the next phase of the Risk Register.

Risk Ratings and Current Mitigations

Unmitigated Risks

Likelihood [1 - 5] 5
Spread [1 - 5] 3
Impact [1 - 5] 4
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 20
UK Relative Risk Rating [1 - 125] 100

Current Mitigations

  • show / hide

Key mitigation for pest

Regulated pest free area pest (part UK), eradication and containment programme



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 Status Notes
Austria Present
Belgium Present
Bulgaria Present
Belarus Present
Switzerland Present
Germany Present
Spain Present
France Present
United Kingdom Present (Limited)
Croatia Present
Italy Present
Moldova Present
Netherlands Present
Poland Present
Romania Present
Serbia Present
Russia Present
Sweden Present
Slovenia Present
Turkey Present
Ukraine Present

Type of Pest

  • Insect (Lepidoptera)

Host or Industry at Risk

  • show / hide


Major Hosts

  • Quercus L.
  • Quercus calliprinos Webb
  • Quercus cerris L.
  • Quercus petraea (Matt.) Liebl.
  • Quercus pubescens Willd.
  • Quercus pyrenaica Willd.
  • Quercus robur L.
  • Quercus boissieri

Threats to Protected Cultivation

Forest Tree Pests and Pathogens

  • Broadleaved

Further Information

PRA Availability

UK (2007), EFSA (2009)

Regulation and EPPO listing

  • show / hide

Regulated pest free area pest (part of UK and other parts of Europe)

Actions Indicated

  • show / hide


Surveillance and statutory action against findings in line with legislation.

General Comments

Pest of oak which has both plant and human health impacts. Regulation in place to protect pest free areas. Containment strategy in place to prevent spread from infected sites in London. Stakeholder groups will be a valuable contribution to monitoring.

Risk Records for this Pest