NAME OF THE ORGANISM: Leek yellow stripe virus (LYSV00)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different to the preferred name):
Pest category:
Viruses and viroids
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: Vegetable propagating and planting material (other than seeds) sector
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Vegetable propagating and planting material (other than seeds) sector
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
Presence in the EU:
Yes
List of countries (EPPO Global Database):
Belgium (2006); Denmark (2006); Finland (2006); France (2006); Germany (2006); Greece (2006); Italy (2006); Italy/Sicilia (2006); Netherlands (2006); Slovenia (2006); Sweden (2006)
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: Allium porrum (ALLPO) for the Vegetable propagating and planting material (other than seeds) sector.
Origin of the listing:
2 - Vegetable seedling sector: Commission Directive 93/61/EC
Plants for planting:
Plants 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:
This virus is reported in literature in garlic, leek and shallot but not for onion (Compendium of Onion and Garlic Diseases, 2008). It is transmitted non-persistently by Aphis fabae and Myzus persicae but not through seed of leek (Bos, 1981).
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
Plant growth is less affected than in the case of OYDV, but yield reductions may be significant (30-60% depending on the variety) (Lot & Delécolle, 1996).
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Medium
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:
Not recommended for listing as an RNQP: This pest/host/intended use combination meets all the criteria for RNQP status but 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 (leek is usually produced from seeds, and this virus is not transmitted through leek seeds).
8 - Tolerance level:
Is there a need to change the Tolerance level:
No
Proposed Tolerance levels:
Delisting.
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
Delisting.
REFERENCES: