|Brussels, 14th January 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 1
Current regulatory status
Cryphonectria parasitica (Murrill) Barr is currently regulated in Annex IIAII (c).3 of Council Directive 2000/29/EC on plants of Castanea Mill and Quercus L., intended for planting, other than seeds.
Specific requirements are laid down in Annex III (Part A) as regards prohibition of introduction of plants of Castanea Mill., and Quercus L., with leaves, other than fruit and seeds, from non-European countries; Annex IV as regards special requirements which must be laid down by all Member States for the introduction and movement of plants, plant products and other objects into and within all Member States; Annex V as regards plant health inspection before certain host plants can enter the European territory.
Supplementary requirements are laid down for Protected Zones (CZ, IE, SE, UK) as part of Annex IIB and Annex IVB.
Identity of the pest
The fungus can be identified either from its characteristic fruiting structures formed in situ, after incubation under damp conditions, or by isolation in culture. A DNA-based identification is possible to identify the specific strain. C. parasitica is a clear taxonomic entity and sensitive and reliable methods exist for its detection and identification, as well as for its discrimination from other related fungal plant pathogens.
Distribution of the pest
C. parasitica is reported in 15 EU MSs. In 6 MSs (Croatia, Hungary, Italy, Portugal, Slovenia, and France), the pathogen is present in all (or almost all) of the areas where the host plants occur; in 7 MSs (Austria, Belgium, Bulgaria, Germany, Greece, Slovak Republic, and Spain) with a restricted distribution; and, in 2 MSs, it is under eradication (the Netherlands and the UK). In the Czech Republic, the pathogen was eradicated. Literature confirms the presence of C. parasitica also in Romania and Greece.
No information is available in the literature or in the EPPO PQR database on the pest status in Cyprus, Latvia, Lithuania, Luxembourg, Iceland or Norway. C. parasitica is already well spread within the PRA area, except in restricted area.
Potential for establishment and spread in the PRA area
The three main hosts of C. parasitica are American sweet chestnut (Castanea dentata), European sweet chestnut (C. sativa) and Durmast oak (Quercus petrea). The main host species are present in the risk assessment area. The fungus seems to be present in most of the countries where the sweet chestnut Castanea sativa is present in high quantities (except UK).
There are no obvious ecological or climatic factors limiting the potential establishment and spread of the pathogen in the EU MSs where the pest is not known to occur.
C. parasitica can spread locally by wind and/or rain, but might also occasionally be carried by other agents, such as arthropods and birds. C. parasitica can spread over long distances via the movement of infected host plants for planting (rootstocks, scions, grafted plants, self-rooted plants, etc.), particularly asymptomatic (i.e. either latently infected or tolerant to infection) and infected wood with bark.
Potential for consequences in the PRA area
No or very little impact is noted on Quercus in some MSs (e.g. FR). Regulation on Quercus seems only justified in order to prevent introduction into non-contaminated areas.
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.
Overall, C. parasitica can have considerable direct or indirect impacts in the EU, including economic and environmental effects.
Considering the wide distribution of this pest, and the fact that eradication and containment measures are not efficient any longer in Member States where the pathogen has existed for a long time, the Working Group suggests listing this organism as a Regulated Non-Quarantine Pest2.
However, the protected zone status should be maintained as a possibility for those Member States that have proved to be still free from C. parasitica. Also Annex III (Part A) as regards prohibition of introduction of plants of Castanea Mill., and Quercus L., with leaves, other than fruit and seeds, from non-European countries, should remain. Equivalent requirements for imports and movement of host plants have to be set in order to retain the same level of protection.
Lastly, the Working Group highlights that the classification as a RNQP would promote the development of the use of hypovirulence (through inoculation).
The Pest Risk Assessment of EFSA does not need to continue at this stage, unless Member States request a Protected Zone Quarantine status.