Year: 2018
Type: article
Abstract: Following a request from the European Commission, the EFSA Plant Health Panel performed a pest categorisation of Melampsora medusae, a well-defined and distinguishable fungal species of the family Melampsoraceae.The pathogen is regulated in Annex IAI of Council Directive 2000/29/EC as a harmful organism whose introduction into the EU is banned.M. medusae is a heteroecious rust fungus with Populus spp. as primary telial hosts and various conifers (Larix, Pinus, Pseudotsuga, Abies, Picea and Tsuga spp.) as secondary aecial hosts.M. medusae is native to North America and has spread to South America, Africa, Asia, Oceania, as well as the EU, where M. medusae f. sp.deltoidae has been reported with a restricted distribution and low impacts from Belgium, south-west France and southern Portugal.The pest could spread to other EU countries, via dissemination of spores, movement of host plants for planting and cut branches.Climate is assumed not to be a limiting factor for the establishment of the pathogen in the EU.M. medusae is the most widespread and important Melampsora rust in North America.In western Canada, extensive damage has been reported to conifers and Populus spp. in nurseries and plantations as well as in woodlands.M. medusae is damaging in both Australia and New Zealand.The pest could have economic and environmental impacts in the EU if aggressive isolates of M. medusae were introduced into the EU.Import prohibition of host plants for planting is an available measure to reduce the risk of further introductions.Some resistant Populus cultivars are available.Moreover, increasing the genetic diversity of poplar plantations can prevent disease impacts.The main uncertainty concerns the factors explaining the low pathogenicity of the populations of M. medusae present in the EU.The criteria assessed by the Panel for consideration as a potential quarantine pest are met (the pest is present, but with a restricted distribution, and is officially under control).Given that plants for planting are not the main pathway of spread, not all criteria for consideration as a regulated non-quarantine pest are met.
Source: EFSA Journal
Authors: EFSA Panel on Plant Health (PLH), Michael Jeger, Claude Bragard, David Caffier, Thierry Candresse, Elisavet Chatzivassiliou, Katharina Dehnen‐Schmutz, Gianni Gilioli, Jean‐Claude Grégoire, Josep Anton Jaques Miret, Alan MacLeod, Maria Navajas Navarro, Björn Niere, Stephen Parnell, Roel Potting, Trond Rafoss, Vittorio Rossi, Gregor Urek, Ariena Van Bruggen, Wopke Van der Werf, Jonathan West, Stephan Winter, Johanna Boberg, Paolo Gonthier, Marco Pautasso
Language: English
Subfield: Microbiology
Field: Immunology and Microbiology
Domain: Life Sciences
SDG: Life on land
Open Access status: gold
Estimated APC paid: $2,400
OpenAlex ID: W2854238301