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.
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Claims 8
Claim · model-written summary
Populus species are primary telial hosts and several conifer genera are secondary aecial hosts of M. medusae.
- Interactor
- M. medusae
Melampsora medusaee0pathogen - Outcome
- primary telial hostse0
PopulusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“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.”
Claim · model-written summary
M. medusae has had low impacts and restricted distribution in parts of the EU.
- Taxon
- M. medusae f. sp. deltoidaeMelampsora medusae f. sp. deltoidise0
- Outcome
- low impactse0
- Setting
- Belgium, south-west France and southern Portugale0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“M. medusae f. sp. deltoidae has been reported with a restricted distribution and low impacts from Belgium, south-west France and southern Portugal.”
Claim · model-written summary
Extensive M. medusae damage has been reported in western Canadian conifer and poplar nurseries, plantations and woodlands.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In western Canada, extensive damage has been reported to conifers and Populus spp. in nurseries and plantations as well as in woodlands.”
Claim · model-written summary
M. medusae is damaging in Australia and New Zealand.
- Taxon
- M. medusaeMelampsora medusaee0
- Outcome
- damaginge0
- Setting
- Australia and New Zealande0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“M. medusae is damaging in both Australia and New Zealand.”
Claim · model-written summary
Aggressive M. medusae isolates could cause economic and environmental impacts in the EU.
- Interactor
- M. medusaeMelampsora medusaee0pathogen
- Outcome
- economic and environmental impactse0
- Qualifier
- if aggressive isolates of M. medusae were introduced into the EUe0
- Setting
- EUe0
Not reportedTaxon
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The pest could have economic and environmental impacts in the EU if aggressive isolates of M. medusae were introduced into the EU.”
Claim · model-written summary
Import prohibition of host plants for planting can reduce further introductions.
- Treatment
- Import prohibition of host plants for plantinge0
- Outcome
- reduce the risk of further introductionse0
Not reportedTaxon
Verbatim
e0“Import prohibition of host plants for planting is an available measure to reduce the risk of further introductions.”
Claim · model-written summary
Increasing poplar plantation genetic diversity can prevent disease impacts.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increasing the genetic diversity of poplar plantations can prevent disease impacts.”
Claim · model-written summary
Resistant Populus cultivars are available.
- Outcome
- resistant Populus cultivarse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Some resistant Populus cultivars are available.”