NAME OF THE ORGANISM: Ditylenchus dipsaci (DITYDI)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different to the preferred name):
Pest category:
Nematoda
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?
Yes
Is the pest defined at the species level or lower?:
Yes
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
Conclusion:
- 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.
- 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?
No
Presence in the EU:
Yes
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)
Conclusion:
candidate
Justification (if necessary):
Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/).
HOST PLANT N°1: Sternbergia (1STBG) for the Ornamental sector.
Origin of the listing:
RNQP Questionnaire
Plants for planting:
Bulbs and corms intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
No
Conclusion:
Evaluation continues
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
Yes
Conclusion:
Candidate
Justification:
Sternbergia lutea is a bulbous flowering plant in the family Amaryllidaceae, called winter daffodil, autumn daffodil or yellow autumn crocus. They are stated as being damaged by narcissus eelworm (D. dipsaci) (RHS, 2017). During the Project Sternbergia was stated to be a host plant of D. dipsaci (NL NPPO).
D. dipsaci is currently regulated for many of its host plants but not for Sternbergia. The organism was found in lots of bulbs of Sternbergia, imported from Turkey, in 2004 (Phytosanitary report available at http://edepot.wur.nl/212728). The organism does not only pose a threat to the cultivation of Sternbergia but also to other crops because the organism can survive for many years in soil.
D. dipsaci is currently regulated for many of its host plants but not for Sternbergia. The organism was found in lots of bulbs of Sternbergia, imported from Turkey, in 2004 (Phytosanitary report available at http://edepot.wur.nl/212728). The organism does not only pose a threat to the cultivation of Sternbergia but also to other crops because the organism can survive for many years in soil.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
They are stated as being damaged by narcissus eelworm (D. dipsaci) (RHS, 2017). The organism is known to cause major impacts in other host crops, including complete failure of host crops (e.g. onions, garlic, cereals, legumes, strawberries, ornamental plants, especially flower bulbs).
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?
No
Conclusion:
Candidate
Justification:
6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?
Yes
Conclusion:
candidate
Justification:
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Yes
Conclusion:
Candidate
Justification:
CONCLUSION ON THE STATUS:
Recommended for listing as an RNQP, based on data.
8 - Tolerance level:
Is there a need to change the Tolerance level:
Yes
Proposed Tolerance levels:
Zero tolerance based on visual examination.
9 - Risk management measures:
Is there a need to change the Risk management measure:
Yes
Proposed Risk management measure:
(a) The plants have been inspected and no symptoms of Ditylenchus dipsaci have been observed on the lot since the beginning of the last complete cycle of vegetation;
or
(b) The bulbs are found substantially free from symptoms of Ditylenchus dipsaci and packed for sale to the final consumer.
or
(b) The bulbs are found substantially free from symptoms of Ditylenchus dipsaci and packed for sale to the final consumer.
REFERENCES:
- RHS (Royal Horticultural Society) (2017) Sternbergia lutea winter daffodil. Website article. UK. Accessed 27/7/2017 at https://www.rhs.org.uk/Plants/17789/i-Sternbergia-lutea-i/Details;