Regulated non-quarantine pest Project

An EU funded project for the benefit of the whole EPPO region

NAME OF THE ORGANISM: Ditylenchus dipsaci (DITYDI)


Name as submitted in the project specification (if different to the preferred name):

Pest category:

1- Identity of the pest/Level of taxonomic listing:

Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?

Is the pest defined at the species level or lower?:

Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?
  • Not relevant: Ornamental sector
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant

  • Candidate: Ornamental sector
Justification (if necessary):
Remark for ornamentals:
- Allium: There is a large number of Allium species (and within the species, varieties) that are used as ornamentals.
Therefore it is suggested to include all Allium for ornamental use in the present evaluation.
- Ismene (host plant for D. dipsaci as mentioned in Directive 2000/29/EC) is nowadays named Hymenocallis for cultivated ornamental species and varieties.

2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?

Presence in the EU:

List of countries (EPPO Global Database):
Austria (1993); Belgium (2007); Bulgaria (1993); Croatia (1996); Cyprus (1993); Czech Republic (1994); Denmark (1993); Estonia (1994); Finland (1993); France (2010); Germany (2014); Greece (1996); Hungary (2001); Ireland (1998); Italy (1992); Italy/Sicilia (2002); Latvia (2013); Lithuania (1998); Malta (1995); Netherlands (2015); Poland (2012); Portugal (1992); Portugal/Azores (1994); Romania (2011); Slovakia (2007); Slovenia (2003); Spain (2007); Sweden (1993); United Kingdom (1993); United Kingdom/England (1994); United Kingdom/Scotland (1994)


Justification (if necessary):
Data of the presence of this pest on the EU territory are available in EPPO Global Database (

HOST PLANT N°1: Allium schoenoprasum (ALLSC) for the Ornamental sector.

Origin of the listing:

Plants for planting:
Plants intended for planting

3 - Is the pest already listed in a PM4 standard on the concerned host plant?
Evaluation continues

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
Not candidate

A literature and Google search for this species (Allium schoenoprasum), being used as an ornamental plant, as opposed to a vegetable plant, did not locate any references. The analysis of the RNQP status continues on the whole Allium genus for ornamental purpose (see corresponding summary sheet).

Disqualified: evaluation of the RNQP status continues for the whole Allium genus (see corresponding summary sheet)

8 - Tolerance level:

Is there a need to change the Tolerance level:

Proposed Tolerance levels:
Delisting (Covered by the listing of the whole Allium genus).

9 - Risk management measures:

Is there a need to change the Risk management measure:

Proposed Risk management measure:
Delisting (Covered by the listing of the whole Allium genus).

  • CABI (Centre for Agricultural Bioscience International) (2015) Online. Datasheets Ditylenchus dipsaci (stem and bulb nematode). Invasive species compendium. CABI, Wallingford, UK. Available from;
  • EU COM (2016) Recommendation of the Working Group on the Annexes of the Council Directive 2000/29/EC – Section II – Listing of Harmful Organisms as regards the future listing of Ditylenchus dipsaci (Kuhn) Filipvejev;
  • Green CD & Sime S (1979) The dispersal of Ditylenchus dipsaci with vegetable seeds. Annals of Applied Biology 92 No.2, 263-270;
  • Monnet Y & Thibault O (2003) Diseases and pests of chives. PHM Revue Horticole 2003 No.444,, 32-33;