UK Risk Register Details for Ditylenchus dipsaci

Common Names

  • Beef stem nematode
  • Brown ring disease of hyacynth
  • Bud and stem nematode
  • Clover stem nematode
  • Eelworm, bulb
  • Eelworm, stem and bulb
  • Nemadode, stem
  • Nematode, stem and bulb
  • Onion bloat
  • Onion stem nematode
  • Phlox stem nematode
  • Ring disease of bulbs
  • Stem and bulb nematode
  • Stem nematode
  • Tulip root nnematode

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] 1
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

EU regulated pest



Industry Scheme

Contingency Plan



Mitigated Risks

Likelihood [1 - 5] 2
Spread [1 - 5] 1
Impact [1 - 5] 3
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 6
UK Relative Risk Rating [1 - 125] 30

Proposed Actions

Proposed Actions



Management By Industry

Targeted Survey


Contingency Plan



Distribution and Pest Details


Country Status Notes
Europe Present cosmopolitan
United Kingdom Present (Widespread)
North America
Canada Present
Costa Rica Present
Dominican Republic Present
Haiti Present
Mexico Present
United States Present (Widespread)
South America
Argentina Present
Bolivia Present
Brazil Present
Chile Present
Colombia Present
Ecuador Present
Peru Present
Paraguay Present
Uruguay Present
Venezuela Present
Australia Present (Limited)
New Zealand Present (Widespread)
Algeria Present
Kenya Present
Morocco Present
Reunion Present
Tunisia Present
South Africa Present (Limited)
China Present
Israel Present (Widespread)
India Present
Iraq Present
Iran Present
Japan Present
Kyrgyzstan Present
South Korea Present
Kazakhstan Present
Oman Present
Pakistan Present
Syria Present
Uzbekistan Present
Yemen Present

Type of Pest

  • Nematode (Tylenchida)

Host or Industry at Risk

  • show / hide

Total outdoor production

Major Hosts

  • Allium cepa L.
  • Allium sativum L.
  • Avena sativa L.
  • Beta vulgaris L.
  • Fragaria ananassa (F. x ananassa) Duch.
  • Medicago sativa L.
  • Solanum tuberosum L.
  • Vicia faba L.

Threats to Protected Cultivation

Forest Tree Pests and Pathogens

Further Information

PRA Availability

PRA not available

EU and EPPO Listing


Actions Indicated

  • show / hide


Deregulation to reflect the fact this pest no longer meets the criteria for quarantine pest.

General Comments

Damaging nematode, widespread in UK and elsewhere, main risk is if it reaches propagating material. EU regulations and the Plant Health Propagation Scheme mitigates against this, subject to EFSA review and likely candidate for deregulation.

Risk Records for this Pest