| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Ditylenchus dipsaci (DITYDI)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
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: 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:
Yes
List of countries (EPPO Global Database):
Austria (1993); Belgium (2017); Bulgaria (1993); Croatia (1996); Cyprus (2019); Czech Republic (1994); Denmark (2019); Estonia (1994); Finland (1993); France (2010); Germany (2021); Greece (1996); Hungary (2001); Ireland (1998); Italy (1992); Italy/Sicilia (2002); Latvia (2013); Lithuania (1998); Malta (1995); Netherlands (2022); Poland (2012); Portugal (1992); Portugal/Azores (1994); Romania (2011); Slovakia (2007); Slovenia (2017); Spain (2007); Sweden (1993)
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: Ribes (1RIBG) 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
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):
No
Conclusion:
Not candidate
Justification:
• Plant: yes (important, but no information on Ribes)
• Seed: yes (but not for Ribes)
• Pollen: no
• Soil: yes
Ditylenchus dipsaci has a very wide host-plant range (EPPO, 2023), however, there is no reference to Ditylenchus dipsaci in Ribes spp. (CAB abstract search dd 6/May/2023).
Some plant species are very good host-plants, which means that the nematode propagates well on these host plants, other host plant do not sustain D. dipsaci. The lifecycle of D. dipsaci is mostly above ground (in plant material), however, it can survive well in soil, especially on heavy clay soils (> 10 years), on sandy soils less (aaltjesschema, 2019).
In international trade, D. dipsaci is liable to be carried on dry seeds and planting material of host plants. In the field, D. dipsaci migration to the soil surface, where infection occurs, is initiated by rainfall or irrigation (Barbercheck and Duncan, 2004). Regular rainfall in spring or autumn just after sowing favors nematode infection.
• Seed: yes (but not for Ribes)
• Pollen: no
• Soil: yes
Ditylenchus dipsaci has a very wide host-plant range (EPPO, 2023), however, there is no reference to Ditylenchus dipsaci in Ribes spp. (CAB abstract search dd 6/May/2023).
Some plant species are very good host-plants, which means that the nematode propagates well on these host plants, other host plant do not sustain D. dipsaci. The lifecycle of D. dipsaci is mostly above ground (in plant material), however, it can survive well in soil, especially on heavy clay soils (> 10 years), on sandy soils less (aaltjesschema, 2019).
In international trade, D. dipsaci is liable to be carried on dry seeds and planting material of host plants. In the field, D. dipsaci migration to the soil surface, where infection occurs, is initiated by rainfall or irrigation (Barbercheck and Duncan, 2004). Regular rainfall in spring or autumn just after sowing favors nematode infection.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
No
Justification:
Unknown. No data available.
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:
Remark: Other host plants can be severely affected, but not Ribes. There are no reports in the scientific literature about Ribes as a host for Ditylenchus dipsaci or about its economic impact on this crop.
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:
Crop rotation, although difficult since D. dipsaci has a wide host range
Warm-water treatment of plant material,
Soil fumigation (e.g. products based on metam-sodium), dependent on legislation
Anaerobic Soil Desinfestation (ADS) can result in 97-99% population decline (Visser et al., 2017)
Soil inundation
Warm-water treatment of plant material,
Soil fumigation (e.g. products based on metam-sodium), dependent on legislation
Anaerobic Soil Desinfestation (ADS) can result in 97-99% population decline (Visser et al., 2017)
Soil inundation
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 of Ribes being a host plant could be found. No economic impact reported on this host.
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:
- Aaltjesschema (2019). Website on information and crop rotation for various crops. The website is s product of Wageningen UR, nematology PPO-AGV. Website is accessible until 31 March 2024, only information for perennial plants and fruit crops will still be available. https://www.aaltjesschema.nl/Home.aspx
- Anonymous (2016) Brochure stengelalen [Dutch]. https://edepot.wur.nl/405964
- Barbercheck ME & Duncan LW (2004) Abiotic factors. In Gaugler R, Bilgrami AL (Eds.): Nematode behaviour.
- Wallingford. CABI Publishing, pp. 309–344
- EPPO (2024) Ditylenchus dipsaci. EPPO datasheets on pests recommended for regulation. https://gd.eppo.int (accessed 2024-03-21).
- Visser JHM, Molendijk LPG, Feil H, Meints H & Beers T van (2017) Bodem resetten: innovatieve anaerobe grondontsmetting (ASD) tegen schadelijke bodemorganismen : laboratorium- en veldonderzoek naar de effectiviteit van anaerobe grondontsmetting met Herbie (Bodemresetten) en gras ter bestrijding van het maiswortelknobbelaaltje (Meloidogyne chitwoodi), stengelaaltje (Ditylenchus dipsaci), het aardappelcysteaaltjespp en de bodemschimmel Verticillium dahliae, Wageningen : Wageningen University & Research, Praktijkonderzoek