NAME OF THE ORGANISM: Tomato spotted wilt tospovirus (Tomato spotted wilt virus) (TSWV00)
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: 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):
Tomato spotted wilt tosopvirus (TSWV) is a single taxonomic entity (genus Tospovirus: family Bunyaviridae). In 2015 it was proposed to change the name of the virus from Tomato spotted wilt virus to Tomato spotted wilt tospovirus (ICTV, 2015; Van Regenmortel et al., 2015). It has been ratified in 2016 for all the family of the Bunyaviridae.
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):
Belgium (2014); Bulgaria (2013); Croatia (1999); Cyprus (2011); Czech Republic (2011); France (2013); Germany (2011); Greece (2002); Greece/Kriti (1994); Hungary (2012); Ireland (1993); Italy (2013); Italy/Sicilia (1994); Italy/Sardegna (2006); Lithuania (1998); Malta (2011); Netherlands (2015); Portugal (2011); Portugal/Madeira (2001); Romania (2011); Slovenia (2011); Spain (2016); Spain/Islas Canárias (2011); Spain/Islas Baleares (2011); Sweden (1998); United Kingdom (2011); United Kingdom/England (1995); United Kingdom/Scotland (1995); United Kingdom/Channel Islands (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/). This pest is a candidate for the RNQP status according to the IIA2AWG
HOST PLANT N°1: Lactuca sativa (LACSA) for the Ornamental sector.
Origin of the listing:
IIA2AWG
Plants for planting:
Plants intended for planting, other than 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):
Yes
Conclusion:
Candidate
Justification:
Some lettuce varieties cab grown for ornamental use though no specific information on them was obtained regarding TSWV, in a brief search.
TSWV has an extremely wide host range with more than 1 300 plants including agricultural crops, wild and weed species (Parrella et al., 2003; Peters, 2003). TSWV is a systemic pathogen and, as such, it is very efficiently transmitted by all vegetative multiplication techniques (EFSA-PLH, 2012). The virus is transmitted by thrips in a persistent propagative mode (Ullman et al., 1993; Wijkamp et al., 1993). Because of the persistence of TSWV in the vectors, the virus can be carried by infected plant material but also by viruliferous thrips, which can be present on a consignment that is infected with TSVW or even on consignments of non-host plants of the virus. The interception reports in EUROPHYT (very few) indicate that TSWV is found mostly in consignments of ornamentals. No interception has been reported on Lactuca sativa from 1996 to 2012. TSWV and viruliferous thrips are being transported in living planting material and will survive transport and storage as long as their hosts remain alive (EFSA-PLH, 2012). The plants for planting are a significant pathway compared to other pathways.
TSWV has an extremely wide host range with more than 1 300 plants including agricultural crops, wild and weed species (Parrella et al., 2003; Peters, 2003). TSWV is a systemic pathogen and, as such, it is very efficiently transmitted by all vegetative multiplication techniques (EFSA-PLH, 2012). The virus is transmitted by thrips in a persistent propagative mode (Ullman et al., 1993; Wijkamp et al., 1993). Because of the persistence of TSWV in the vectors, the virus can be carried by infected plant material but also by viruliferous thrips, which can be present on a consignment that is infected with TSVW or even on consignments of non-host plants of the virus. The interception reports in EUROPHYT (very few) indicate that TSWV is found mostly in consignments of ornamentals. No interception has been reported on Lactuca sativa from 1996 to 2012. TSWV and viruliferous thrips are being transported in living planting material and will survive transport and storage as long as their hosts remain alive (EFSA-PLH, 2012). The plants for planting are a significant pathway compared to other pathways.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
?
Justification:
TSWV is considered a very important pathogen of tomatoes. A similarly high impact on a range of other horticultural crops, such as pepper, potato, eggplant, lettuce and broad beans, is observed (Kormelink et al.,1998; EFSA, 2012). While quantitative data on yield loss in crops and ornamentals are generally lacking, losses from TSWV diseases are considered very serious (Scholthof et al., 2011; EFSA, 2012). No details of any impact on ornamental lettuce could be found, though it is assumed they may react to infection in a similar way, i.e. pronounced symptoms occur on leaves of lettuce, and causing serious disease (EFSA PLH, 2012)
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
Conclusion:
Candidate
Justification:
Impact is evaluated as major, by extrapolation from the vegetable use.
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?
No
Conclusion:
Candidate by default
Justification:
Uncertainty exists due to the lack of precise information on the prevalence and the economic impact of TSWV in Lactuca sativa for ornamental purposes.
CONCLUSION ON THE STATUS:
Not recommended for listing as an RNQP: Experts concluded that ornamental lettuce is a very minor ornamental host. Experts commented that there is a lack of data on ornamental Lactuca sativa, therefore it is questionable whether this pest/host/intended use combination meets all the criteria for RNQP status. The requirement for absence of visual symptoms on the traded material (current general 'Substantially free from' requirement in the EU) was considered to be sufficient.
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:
- Daughtrey ML, Jones RK, Moyer JW, Daub ME & Baker JR (1997) Tospoviruses strike the greenhouse industry—INSV has become a major pathogen on flower crops. Plant Disease 81, 1220–1230;
- EU COM (2016) 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 Tomato spotted wilt virus ;
- EFSA Panel on Plant Health (PLH) (2012) Scientific Opinion on the risk to plant health posed by Tomato spotted wilt virus to the EU territory with identification and evaluation of risk reduction options. EFSA Journal 2012;10(12):3029. [64 pp.] doi:10.2903/j.efsa.2012.3029. Available online: www.efsa.europa.eu/efsajournal;
- International Committee on Taxonomy of Viruses (ICTV) (2015) Implementation of non-Latinized binomial species names in the family Bunyaviridae;
- Kormelink R, Peters D & Goldbach R (1998) Tospovirus genus. Association of Applied Biologists, Descriptions of Plant Viruses September 1998, 363, 1–14. Available from http://www.dpvweb.net/dpv/showadpv.php?dpvno=363;
- Parrella G, Gognalons P, Gebre-Selassie K, Vovlas C and Marchoux G (2003) An update of the host range of tomato spotted wilt virus. Journal of Plant Pathology 85, 227–264;
- Scholthof KB, Adkins S, Czosnek H, Palukaitis P, Jacquot E, Hohn T, Hohn B, Saunders K, Candresse T, Ahlquist P, Hemenway C and Foster GD (2011) Top 10 plant viruses in molecular plant pathology. Molecular Plant Pathology, 12, 938–954;
- Van Regenmortel MH, Burke DS, Calisher CH, Dietzgen RG, Fauquet CM, Ghabrial SA, Jahrling PB, Johnson KM, Holbrook MR, Horzinek MC, Keil GM, Kuhn JH, Mahy BW, Martelli GP, Pringle C, Rybicki EP, Skern T, Tesh, RB, Wahl - Jensen V, Walker PJ & Weaver SC (2010) A proposal to change existing virus species names to non - Latinized binomials. Arch. Virol. 2010 155, 1909 - 1919;
- Verhoeven TJ & Roenhorst JW (1994) Tomato spotted wilt virus: ecological aspects in ornamental crops in the Netherlands from 1989 up to 1991. Acta Horticulturae, 377, 175–182;
- Verhoeven TJ & Roenhorst JW (1998) Occurrence of tospoviruses in the Netherlands. Proceedings of the Fourth International Symposium on Tospoviruses and thrips in Floral and Vegetable Crops, Wageningen, Netherlands. May 2-6 1998, 77-80;