NAME OF THE ORGANISM: Viruses (Mosaic symptoms and leaf roll virus together) 1VIRUD*
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
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?
No
Is the pest defined at the species level or lower?:
No
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?
- Yes: Seed potato sector
If necessary, please list the species:
Six viruses are already specifically listed at the species level in the EU Marketing Directives for seed potatoes (Potato virus Y, Potato virus X, Potato virus M, Potato virus S, Potato virus A and Potato leaf roll virus). Another virus (TSWV) was specifically submitted as a candidate for the RNQP status by the IIA2 AWG. Ten additional viruses are listed in EPPO PM 4/28 Standard. Therefore the list is restricted to the leaf roll virus and to the viruses causing mosaic symptoms mentioned previously.
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Not candidate: Seed potato sector
Justification (if necessary):
Mosaic symptoms and leaf roll virus together' is not a single taxonomic entity. Six viruses are already specifically listed at the species level in the EU Marketing Directives for seed potatoes (Potato virus Y, Potato virus X, Potato virus M, Potato virus S, Potato virus A and Potato leaf roll virus). Another virus (TSWV) was specifically submitted as a candidate for the RNQP status by the IIA2 AWG. Ten additional viruses are listed in EPPO PM 4/28 Standard. In the replies to the RNQP questionnaire, 2 EU Member States (FR and SI) and ESA considered this entry as important. FR considered that these viruses could be listed at a lower taxonomic level (ie detailed type of virus) but think it is important to keep such global tolerances for viruses in the regulation because they are mainly controlled through visual inspections of field on the basis of the visible symptoms on growing plants. Moreover, the symptoms are often similar and combinations of viruses can be present in plants. On the other hand, SI proposed to keep "Viruses (Mosaic symptoms and leaf roll virus together)" listed as a RNQP. Experts concluded that viruses should be listed individually. However the measures based on visual inspection of mosaic symptoms and leaf roll together should remain in the Marketing Directive.
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):
Conclusion:
Justification (if necessary):
HOST PLANT N°1: Solanum tuberosum (SOLTU) for the Seed potato sector.
Origin of the listing:
5 - Seed potato sector: Council Directive 2002/56/EC
Plants for planting:
Plants intended for planting, other than [true] seeds
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):
Conclusion:
Justification:
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Justification:
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?
Conclusion:
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?
Conclusion:
Justification:
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
Justification:
CONCLUSION ON THE STATUS:
Disqualified: A listing of such symptoms as a RNQP is not possible under the RNQP definition: it is not a single taxonomic entity. However it is proposed to list the targeted viruses individually, and to maintain such a general requirement and threshold for all these viruses (Mosaic symptoms and leaf roll virus together) in the relevant Marketing Directive.
8 - Tolerance level:
Is there a need to change the Tolerance level:
?
Proposed Tolerance levels:
The technical judgment of the SEWG was that a 6% tolerance of visual symptoms in the growing seed crop is not sufficiently strict to ensure less than 10% virus disease in the subsequent ware crop. Either a tighter tolerance or other measures such as post-harvest tuber testing are required to achieve this objective.
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
REFERENCES: