| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Ilarvirus BSV (blueberry shock virus) (BLSHV0)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
Blueberry shock virus
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: Fruits (including hops) sector
If necessary, please list the species:
-
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Fruits (including hops) sector
Justification (if necessary):
2 – Status in the EU:
Is this pest already a quarantine pest for the whole EU?
No
Presence in the EU:
No
List of countries (EPPO Global Database):
-
Conclusion:
Not candidate
Justification (if necessary):
HOST PLANT N°1: Vaccinium (1VACG) for the Fruits (including hops) sector.
Origin of the listing:
Commission Implementing Directive (EU) 2014/98/EU and Commission Implementing Regulation (EU) 2019/2072
Plants for planting:
Plants intended for planting, including seeds and pollen
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
Yes
Conclusion:
Evaluation continues
Justification (if necessary):
EPPO Standard PM 4-18 Certification scheme for Vaccinium lists 'Blueberry shock ilarvirus' but indicates that it does 'not occur in vaccinium in the EPPO region, but form a potential risk'. This may contradict minimum requirements for RNQP listing and therefore it was proposed to continue the assessment. In the responses to the questionnaire, NL commented that because of its sever impact and absence, the disease could qualify for quarantine status.
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
Yes
Conclusion:
Justification:
The introduction of BlShV into new areas is primarily by virus-infecting planting stock (Polashock & Hillman, 2017). Once present the virus is also pollen and seed transmitted, and by transmitted by pollen feeding arthropods (Bristow & Martin, 1997; Martin & Tzanetakis, 2018).
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
Blueberry: In the year of the first symptoms of blight losses can be 34-90%, recovery limits losses in subsequent years (Bristow and Martin, 2002). For a European blueberry grower, this is not acceptable.
Cranberry: The average marketable berry numbers and the average berry weight were significantly lower in symptomatic uprights. Although bloom returned in uprights in the first and second year after observation of initial symptoms, bloom was still lower (return bloom varied between 5 – 79% of the original bloom) (Thomas-Sharma et al., 2018). For European growers this is not acceptable.
Cranberry: The average marketable berry numbers and the average berry weight were significantly lower in symptomatic uprights. Although bloom returned in uprights in the first and second year after observation of initial symptoms, bloom was still lower (return bloom varied between 5 – 79% of the original bloom) (Thomas-Sharma et al., 2018). For European growers this is not acceptable.
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Major
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
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:
Candidate
Justification:
Pollen transmission can cause infection of neighboring crops (EFSA, PHL, 2014)
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:
Justification:
Start with virus-free material (certified material).
Once established, other measures mighy not prevent infection (pollination by bees is necessary for production of berries) (Bristow & Martin, 1999).
Once established, other measures mighy not prevent infection (pollination by bees is necessary for production of berries) (Bristow & Martin, 1999).
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: no reports outside North America. It should be further considered for regulation as a Quarantine pest.
8 - Tolerance level:
Is there a need to change the Tolerance level:
Yes
Proposed Tolerance levels:
Delisting
9 - Risk management measures:
Is there a need to change the Risk management measure:
Yes
Proposed Risk management measure:
Delisting
REFERENCES:
- Bristow PR & Martin RR (1999) Transmission and the role of honeybees in field spread of Blueberry shock Ilarvirus, a pollen-bore virus of highbush blueberry. Phytopathology 89: 124-130.
- Bristow PR & Martin RR (2002) Recovery of plants infected with Blueberry Shock Ilarvirus (BlShV). Acta Horticulturae 573: 85-89.
- Martin RR & Tzanetakis IE (2018) High risk blueberry viruses by region in North America; implications for certification, nurseries, and fruit production. Viruses 10(7), 342. doi: 10.3390/v10070342. PMID: 29949859; PMCID: PMC6070900.
- Polashock JJ & Billman BI (2017) Shock. In Compendium of blueberry, cranberry and lingonberry diseases and pests. (eds Polashok, JJ, Caruso FL, Averill AL & Schilder, AC) American Phytopathological Society, St. Paul, Minesota. 72-73.
- Saad N, Olmstead JW, Jones JB, Varsani A & Harmon PF (2021) Known and new emerging viruses infecting blueberry. Plants 14(10), 2172. doi: 10.3390/plants10102172. PMID: 34685980; PMCID: PMC8539497.
- Sayers EW, Bolton EE, Brister JR, Canese K, Chan J, Comeau DC, Connor R, Funk K, Kelly C, Kim S, Madej T, Marchler-Bauer A, Lanczycki C, Lathrop S, Lu Z, Thibaud-Nissen F, Murphy T, Phan L, Skripchenko Y, Tse T, Wang J, Williams R, Trawick BW, Pruitt KD, Sherry ST (2022) Database resources of the national center for biotechnology information. Nucleic Acids Res. 2022 Jan 7;50(D1):D20-D26. doi: 10.1093/nar/gkab1112. PMID: 34850941; PMCID: PMC8728269. (last accessed 24/Apr/2024)
- Thomas-Sharma , S., Wells-Hansen., L., Page, R., Kartanos, V., Saalau-Rojas, E., Lockhart, B.E.L., McManus, P.S. (2018) Characterization of Blueberry shock virus, an emerging Ilarvirus in cranberry. Plant Disease 102: 91-97.