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Pest Categorisation of Arceuthobium Spp. (Non-EU)

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Pest Categorisation of Arceuthobium Spp. (Non-EU) SCIENTIFIC OPINION ADOPTED: 5 July 2018 doi: 10.2903/j.efsa.2018.5384 Pest categorisation of Arceuthobium spp. (non-EU) EFSA Panel on Plant Health (EFSA PLH Panel), Claude Bragard, Francesco Di Serio, Paolo Gonthier, Marie-Agnes Jacques, Josep Anton Jaques Miret, Annemarie Fejer Justesen, Alan MacLeod, Christer Sven Magnusson, Panagiotis Milonas, Juan A Navas-Cortes, Stephen Parnell, Roel Potting, Philippe Lucien Reignault, Hans-Hermann Thulke, Wopke Van der Werf, Antonio Vicent, Jonathan Yuen, Lucia Zappala, Johanna Boberg, Marco Pautasso and Katharina Dehnen-Schmutz Abstract Following a request from the European Commission, the EFSA Panel on Plant Health performed a pest categorisation of Arceuthobium spp. (non-EU), a well-defined and distinguishable group of parasitic plant species of the family Viscaceae, also known as dwarf mistletoes. These are flowering plants parasitising a wide range of conifers of the families Pinaceae and Cupressaceae. Arceuthobium species (non-EU) are regulated in Council Directive 2000/29/EC (Annex IAI) as harmful organisms whose introduction into the EU is banned. Many Arceuthobium species are recognised, with most dwarf mistletoes native in the New World, and north-western Mexico and the western USA as the centre of diversity for the genus. Only two Arceuthobium species are native (and reported to be present) in the EU (Arceuthobium azoricum and Arceuthobium oxycedrum), which are thus not part of this pest categorisation. Hosts of non-EU dwarf mistletoes include species of the genera Abies, Cupressus, Juniperus, Larix, Picea, Pinus, Pseudotsuga and Tsuga. Most Arceuthobium spp. can parasitise more than one species of conifer host. Dwarf mistletoes could enter the EU via host plants for planting and cut branches, but these pathways are closed. They could establish in the EU, as hosts are widespread and climatic conditions are favourable. They would be able to spread following establishment by human movement of host plants for planting and cut branches, as well as natural spread. Should non-EU dwarf mistletoes be introduced in the EU, impacts can be expected on coniferous woodlands, plantations, ornamental trees and nurseries. The main uncertainties concern (i) the precise distribution and host range of the individual Arceuthobium spp. and (ii) the level of susceptibility of conifers native to Europe. For Arceuthobium spp. (non-EU) as a group of organisms, the criteria assessed by the Panel for consideration as a potential quarantine pest are met, while, for regulated non-quarantine pests, the criterion on the pest presence in the EU is not met. © 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority. Keywords: European Union, forest pathology, mistletoe, parasitism, plant pest, quarantine, tree health Requestor: European Commission Question number: EFSA-Q-2018-00035 Correspondence: [email protected] www.efsa.europa.eu/efsajournal EFSA Journal 2018;16(7):5384 Arceuthobium spp. (non-EU): pest categorisation Panel members: Claude Bragard, Katharina Dehnen-Schmutz, Francesco Di Serio, Paolo Gonthier Marie-Agnes Jacques, Josep Anton Jaques Miret, Annemarie Fejer Justesen, Alan MacLeod, Christer Sven Magnusson, Panagiotis Milonas, Juan A. Navas-Cortes, Stephen Parnell, Roel Potting, Philippe Lucien Reignault, Hans-Hermann Thulke, Wopke Van der Werf, Antonio Vicent, Jonathan Yuen and Lucia Zappala. Acknowledgements: The Panel wishes to thank the following for the support provided to this scientific output: Ciro Gardi (EFSA Alpha Unit). Suggested citation: EFSA PLH Panel (EFSA Panel on Plant Health), Bragard C, Di Serio F, Gonthier P, Jacques M-A, Jaques Miret JA, Justesen AF, MacLeod A, Magnusson CS, Milonas P, Navas-Cortes JA, Parnell S, Potting R, Reignault PL, Thulke H-H, Van der Werf W, Vicent A, Yuen J, Zappala L, Boberg J, Pautasso M and Dehnen-Schmutz K, 2018. Scientific Opinion on the pest categorisation of Arceuthobium spp. (non-EU). EFSA Journal 2018;16(7):5384, 23 pp. https://doi.org/10.2903/j.efsa.2018.5384 ISSN: 1831-4732 © 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority. This is an open access article under the terms of the Creative Commons Attribution-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited and no modifications or adaptations are made. Reproduction of the images listed below is prohibited and permission must be sought directly from the copyright holder: Figure 2: © European Environment Agency; Figure 3: © Bugwood.org The EFSA Journal is a publication of the European Food Safety Authority, an agency of the European Union. www.efsa.europa.eu/efsajournal 2 EFSA Journal 2018;16(7):5384 Arceuthobium spp. (non-EU): pest categorisation Table of contents Abstract................................................................................................................................................... 1 1. Introduction................................................................................................................................4 1.1. Background and Terms of Reference as provided by the requestor.................................................. 4 1.1.1. Background ................................................................................................................................4 1.1.2. Terms of Reference ..................................................................................................................... 4 1.1.2.1. Terms of Reference: Appendix 1................................................................................................... 5 1.1.2.2. Terms of Reference: Appendix 2................................................................................................... 6 1.1.2.3. Terms of Reference: Appendix 3................................................................................................... 7 1.2. Interpretation of the Terms of Reference....................................................................................... 8 2. Data and methodologies .............................................................................................................. 8 2.1. Data........................................................................................................................................... 8 2.1.1. Literature search ......................................................................................................................... 8 2.1.2. Database search ......................................................................................................................... 8 2.2. Methodologies............................................................................................................................. 9 3. Pest categorisation ...................................................................................................................... 11 3.1. Identity and biology of the pest.................................................................................................... 11 3.1.1. Identity and taxonomy................................................................................................................. 11 3.1.2. Biology of dwarf mistletoes .......................................................................................................... 11 3.1.3. Intraspecific diversity................................................................................................................... 12 3.1.4. Detection and identification of the pest......................................................................................... 12 3.2. Distribution of dwarf mistletoes .................................................................................................... 14 3.2.1. Distribution of dwarf mistletoes outside the EU.............................................................................. 14 3.2.2. Distribution of dwarf mistletoes in the EU...................................................................................... 14 3.3. Regulatory status ........................................................................................................................ 14 3.3.1. Council Directive 2000/29/EC ....................................................................................................... 14 3.3.2. Legislation addressing the hosts of Arceuthobium spp. (non-EU)..................................................... 15 3.4. Entry, establishment and spread in the EU .................................................................................... 15 3.4.1. Host range.................................................................................................................................. 15 3.4.2. Entry .......................................................................................................................................... 16 3.4.3. Establishment ............................................................................................................................. 16 3.4.3.1. EU distribution of main host plants ............................................................................................... 16 3.4.3.2. Climatic conditions affecting establishment.................................................................................... 16 3.4.4. Spread ......................................................................................................................................
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