Regulated non-quarantine pest Project

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

NAME OF THE ORGANISM: Ditylenchus destructor (DITYDE)


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):
Listing of hosts at the genus level is coherent because D. destructor is highly polyphagous.

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 (2014); Belgium (2007); Bulgaria (2001); Czech Republic (2001); Estonia (2008); France (2001); Germany (2014); Greece (2001); Hungary (1992); Ireland (1998); Latvia (1998); Luxembourg (2001); Netherlands (2015); Poland (2012); Romania (2011); Slovakia (1996); Sweden (1992); United Kingdom (2001); United Kingdom/England (2014); United Kingdom/Scotland (2014)


Justification (if necessary):
The Standing Committee agreed in February 2015 to request EFSA for a complete Pest Risk Assessment before taking a decision about the future regulatory status of this pest in the EU (EU COM, 2015). This complete PRA was published in 2016 (EFSA-PLH 2016). Data of the presence of this pest on the EU territory are available in EPPO Global Database ( The nematode is sporadically present in the majority of EU Member States (EFSA, 2014).

HOST PLANT N°1: Crocus (1CVOG) for the Ornamental sector.

Origin of the listing:

Plants for planting:
Flower bulbs and corms intended for planting

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

Justification (if necessary):
The EPPO classification scheme PM 4/14 requires a nil tolerance at GSI for Grade A material intended for further propagation and for Grade B intended for flowering, but a 1% tolerance is permitted at dry bulb inspection for Grade B, only (EPPO, 2002).

Not recommended for listing as an RNQP: the pest is qualified for RNQP status based on EPPO PM 4 Standard, however the requirement for absence of visual symptoms on the traded material (current general 'Substantially free from' requirement in the EU) is considered to be sufficient on this host.

8 - Tolerance level:

Is there a need to change the Tolerance level:

Proposed Tolerance levels:

9 - Risk management measures:

Is there a need to change the Risk management measure:

Proposed Risk management measure:

  • EFSA Panel on Plant Health (PLH) (2014) Scientific Opinion on the pest categorisation of Ditylenchus destructor Thorne. EFSA Journal 2014;12(9):3834. 31 pp. doi:10.2903/j.efsa.2014.3834;
  • EPPO (2002) PM 4/14(2) Classification scheme for crocus. Bulletin OEPP/EPPO Bulletin 32, 123-128;
  • EU COM (2015) 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 destructor Thorne;
  • EFSA Panel on Plant Health (PLH) (2016). Scientific opinion on the risk to plant health of
  • Ditylenchus destructor for the EU territory. EFSA Journal 14(12):4602, 124 pp. doi:10.2903/j.efsa. 2016.4602;