Regulated non-quarantine pest Project

An EU funded project for the benefit of the whole EPPO region




NAME OF THE ORGANISM: Cryphonectria parasitica (ENDOPA)


GENERAL INFORMATION ON THE PEST

Name as submitted in the project specification (if different to the preferred name):
 

Pest category:
 
Fungi


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
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):
 
Castanea: In the replies to the RNQP Questionnaire for the forestry sector, ENA only proposed the listing of Castanea sativa. However experts proposed a listing at a level higher than species since at least 8 Castanea spp. are identified as being natural or experimental host plants (EFSA, 2014). Experts of the fruit SEWG agreed with the evaluation proposed by the forestry SEWG on Castanea.
Quercus: In the replies to the RNQP Questionnaire for the forestry sector, ENA only proposed the listing of a defined list of species (Quercus suber, Q. rubra, Q. robur, Q. pubescens, Q. petraea, Q. ilex and Q. cerris). However experts proposed a listing at a level higher than species since at least 7 Quercus spp. are identified as being natural or experimental host plants (EFSA, 2014).
Remark: Although intraspecific variability is lower in Europe than in North America, there is great variability between different populations at the local and regional level and the result of subsequent sexual recombination produced by the contact of different populations.

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 (2014); Belgium (2016); Bulgaria (2013); Croatia (2012); France (2014); France/Corse (1999); Germany (2014); Greece (2016); Greece/Kriti (2006); Hungary (2012); Italy (2014); Italy/Sicilia (2006); Italy/Sardegna (2009); Portugal (2014); Portugal/Azores (2007); Portugal/Madeira (2007); Romania (2013); Slovakia (2014); Slovenia (2012); Spain (2014)

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: Castanea (1CSNG) for the Fruits (including hops) 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:
 
C. parasitica can spread via the movement of infected host plants for planting (rootstocks, scions, grafted plants, self-rooted plants, etc.), particularly asymptomatic. Pruning and grafting tools or other equipment used in chestnut nurseries, orchards or forests may potentially spread the disease locally. C. parasitica propagules (ascospores and conidia) can spread locally by wind and/or rain, but might also occasionally be carried by other agents, such as arthropods and birds. However animal vectors are not considered to play a very important role in disease transmission. Many factors may influence the relative importance of ascospores versus conidia and mycelia as the primary inoculum for initiating new cankers or for disease epidemics. Experts considered that infection of seedlings are possible even if it has not been demonstrated so far (EFSA, 2014). Because uncertainty exists about the role of ascospores in disease epidemiology, on natural spread by arthropods and birds, and about the distribution of minor hosts, plants for planting are considered to be a significant pathway for the pest/host/intended use combination. Experts expressed a specific concern about pathway for locally aggressive strains, which would at the same time reduce effectiveness of hypovirulence as control.

5 - Economic impact:

Are there documented reports of any economic impact on the host?
 
Yes

Justification:
 
C. parasitica causes cankers, wilt and diebacks, resulting sometimes in the death of its hosts (when on Castanea). Disease incidence ranges from less than 1% in the recently infested areas (such as Germany) to more than 90% in the countries where the pathogen has existed for a long time (e.g. Italy, France, Switzerland, Portugal, etc.). However, there is no direct relationship between disease incidence and impact (EU COM, 2015).

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:
 
There are several assessments of the potential economic impact depending on the European region considered. The presence of natural hypovirulent strains or more tolerant species must also be taken into account, which means that a uniform response cannot be categorically established at European level (Braganca et al., 2007; Tizado et al., 2012; Bryner et al., 2012). This is why the economic impact is proposed as medium. The presence of the pathogen into the host plant is not acceptable due to its transmission character and to the damage that causes (Anderson et al., 2013).

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:
 
Avoiding human induced introduction of new strains and identifying and promoting local hipovirulence strains have showed an effective method of managing chestnut plantations (Robin et al., 2010; Anderson et al., 2013; Petto et al., 2013).

7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
 
Yes
 
Conclusion:
 
Candidate

Justification:
 
There are sufficient scientific and technical data that make this pathogen meet the criteria for RNQP status

CONCLUSION ON THE STATUS:
 
Recommended for listing as an RNQP, based on data. Plants for planting should be considered as a significant pathway compared to other pathway for the introduction of locally aggressive strains, and absence of regulation of this pest/host combination would reduce effectiveness of hypovirulence as control.


8 - Tolerance level:

Is there a need to change the Tolerance level:
 
No

Proposed Tolerance levels:
 
Zero tolerance, based on the absence of symptoms, for all categories material.

9 - Risk management measures:

Is there a need to change the Risk management measure:
 
Yes

Proposed Risk management measure:
 
Non-certified material (‘CAC’):
(a) Plants produced in areas known to be free from Cryphonectria parasitica;
or
(b) No symptoms of Cryphonectria parasitica have been observed at the site of production since the beginning of the last complete cycle of vegetation;
or
(c) Plants showing symptoms of Cryphonectria parasitica have been rogued out, remaining plants inspected at weekly intervals and no symptoms have been observed at the site of production for at least three weeks before dispatch.

Pre-basic, Basic, Certified material, additional measures could include:
• First two options only.

Justification (if necessary):
 
Experts agreed with measures proposed by the Forestry SEWG.

REFERENCES:
  • EFSA Panel on Plant Health (PLH) (2014) Scientific Opinion on the pest categorisation of Cryphonectria parasitica (Murrill) Barr. EFSA Journal 2014;12(10):3859, 42 pp. doi:10.2903/j.efsa.2014.3859 http://www.efsa.europa.eu/en/efsajournal/doc/3859.pdf;
  • EU COM (2015) 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 Cryphonectria parasitica (Murrill) Barr;