EFSA Journal 2014;12(10):3859 SCIENTIFIC OPINION Scientific Opinion on the pest categorisation of Cryphonectria parasitica (Murrill) Barr1 EFSA Panel on Plant Health (PLH)2, 3 European Food Safety Authority (EFSA), Parma, Italy ABSTRACT The European Commission requested the EFSA Panel on Plant Health to perform a pest categorisation of Cryphonectria parasitica (Murrill) Barr, the fungal pathogen responsible for chestnut blight, a highly destructive disease that kills trees through bark cankers. The pathogen is listed in Annex IIAII of Directive 2000/29/EC. Its identity is clearly defined as C. parasitica (Murrill) Barr and methods exist for its discriminative detection. Several hosts are known, but the main hosts are species of Castanea and Quercus, particularly C. sativa and Q. petraea. These two host species are present in all the EU Member States and the disease has been recorded in most parts of the risk assessment area. C. parasitica is absent in Denmark, Estonia, Finland, Ireland, Malta, Iceland and Norway. No information is available on the presence of the pathogen in Latvia, Lithuania or Luxembourg. In the Czech Republic and Poland, C. parasitica has been eradicated. There are no recognised ecological or climatic factors limiting the potential establishment of the pathogen in the EU Member States where the pathogen is not known to occur. The pathogen can spread by propagules (mainly conidia, but also ascospores and mycelium) that are dispersed by wind, rain or vectors, as well as via the movement of infected or contaminated host plants for planting and bark, particularly asymptomatic ones. Control methods used against C. parasitica include exclusion and eradication, chemical control, host genetic resistance and biological control (hypovirulence). The most successful control methods of C. parasitica in the EU are exclusion and eradication, and hypovirulence. Potential consequences of the damage caused by C. parasitica include yield losses of fruit and wood, reduction in biodiversity and habitat loss for associated organisms. © European Food Safety Authority, 2014 KEY WORDS chestnut, Castanea, chestnut blight , distribution, European Union, impacts, regulated non-quarantine pest 1 On request from the European Commission, Question No EFSA-Q-2014-00262, adopted on 25 September 2014. 2 Panel members: Richard Baker, Claude Bragard, Thierry Candresse, Gianni Gilioli, Jean-Claude Grégoire, Imre Holb, Michael John Jeger, Olia Evtimova Karadjova, Christer Magnusson, David Makowski, Charles Manceau, Maria Navajas, Trond Rafoss, Vittorio Rossi, Jan Schans, Gritta Schrader, Gregor Urek, Irene Vloutoglou, Wopke van der Werf and Stephan Winter. Correspondence: [email protected] 3 Acknowledgement: The Panel wishes to thank the members of the Working Group on Directive 2000/29 Fungi, Imre Holb, Paolo Cortesi, Alberto Santini, Vittorio Rossi, Jan Schans and Irene Vloutoglou, for the preparatory work on this scientific opinion and JRC staff member Giovanni Caudullo, and EFSA staff, Tomasz Oszako, for the support provided to this scientific opinion. Suggested citation: EFSA PLH Panel (EFSA Panel on Plant Health), 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 Available online: www.efsa.europa.eu/efsajournal © European Food Safety Authority, 2014 Cryphonectria parasitica pest categorisation TABLE OF CONTENTS Abstract .................................................................................................................................................... 1 Table of contents ...................................................................................................................................... 2 List of tables and figures .......................................................................................................................... 3 Background as provided by the European Commission ........................................................................... 4 Terms of reference as provided by the European Commission ................................................................ 5 Assessment ............................................................................................................................................... 7 1. Introduction ..................................................................................................................................... 7 1.1. Purpose .................................................................................................................................... 7 1.2. Scope ....................................................................................................................................... 7 2. Methodology and data ..................................................................................................................... 7 2.1. Methodology ........................................................................................................................... 7 2.2. Data ......................................................................................................................................... 9 2.2.1. Literature search ................................................................................................................. 9 2.2.2. Data collection .................................................................................................................... 9 3. Pest categorisation ........................................................................................................................... 9 3.1. Identity and biology of Cryphonectria parasitica .................................................................. 9 3.1.1. Taxonomy ........................................................................................................................... 9 3.1.2. Biology of Cryphonectria parasitica.................................................................................. 9 3.1.3. Intraspecific diversity ....................................................................................................... 11 3.1.4. Detection and identification of Cryphonectria parasitica ................................................ 12 3.1.5. Similarities to other diseases and disorders ...................................................................... 12 3.2. Current distribution of Cryphonectria parasitica ................................................................. 13 3.2.1. Global distribution of Cryphonectria parasitica .............................................................. 13 3.2.2. Distribution of Cryphonectria parasitica in the EU ......................................................... 13 3.3. Regulatory status ................................................................................................................... 16 3.3.1. Council Directive 2000/29/EC ......................................................................................... 16 3.3.2. Marketing Directives ........................................................................................................ 20 3.4. Elements to assess the potential for establishment and spread in the EU ............................. 20 3.4.1. Host range ......................................................................................................................... 20 3.4.2. EU distribution of main host plants .................................................................................. 21 3.4.3. Analysis of the potential distribution of Cryphonectria parasitica .................................. 23 3.4.4. Spread capacity ................................................................................................................. 25 3.4.4.1. Spread by natural means .......................................................................................... 25 3.4.4.2. Spread by human assistance ..................................................................................... 25 3.5. Elements to assess the potential for consequences in the EU ............................................... 26 3.5.1. Potential effects of Cryphonectria parasitica ................................................................... 26 3.5.2. Observed impacts of Cryphonectria parasitica in the risk assessment area .................... 27 3.5.2.1. Direct pest effects .................................................................................................... 27 3.5.2.2. Indirect effects of Cryphonectria parasitica ............................................................ 28 3.6. Currently applied control methods in the EU ....................................................................... 28 3.6.1. Exclusion and eradication ................................................................................................. 28 3.6.2. Cultural practices .............................................................................................................. 29 3.6.3. Chemical control............................................................................................................... 29 3.6.4. Host genetic resistance ..................................................................................................... 29 3.6.5. Biological control ............................................................................................................. 29 3.6.6. Integrated control .............................................................................................................