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: Tigridia (1TIGG) for the Ornamental sector.

Origin of the listing:

Plants for planting:
Miniature cultivars and their hybrids 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):

In a literature search, no specific references to impact or yield effects in Tigridia by D. destructor could be found.

5 - Economic impact:

Are there documented reports of any economic impact on the host?

The reproductive potential of D. destructor is high. It can be assumed that even a small population of D. destructor, present in the soil at the beginning of the growing season, could develop into a very large population causing severe damage to infested host plant. D. destructor can cause significant damage to the below-ground parts (roots, tubers, bulbs) of host crops such as potato and several ornamental plants. It reduces harvest yields of host crops and causes additional damage during storage. In recent years, potato tuber nematodes have caused serious problems on iris and garlic crops in Japan (EFSA, 2014). In a literature search, no specific references to impact or yield effects in Tigridia by D. destructor could be found.
D. destructor cannot survive dessication which may be one of the reasons why this species is much less of a problem than D. dipsaci.

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)

Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?

Is there unacceptable economic impact caused to other hosts (or the same host with a different intended use) produced at the same place of production due to the transfer of the pest from the named host plant for planting?

Not candidate


Disqualified: no specific references to impact or yield effects in Tigridia by D. destructor.

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
  • 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;