Following a request from the European Commission, the EFSA Panel on Plant Health performed a pest
categorisation of Cronartium harknessii, Cronartium kurilense and Cronartium sahoanum, which are
well-defined and distinguishable tree fungal pathogens of the family Cronartiaceae. In 2018, these
species were moved from the genus Endocronartium to the genus Cronartium. These pathogens are
not known to be present in the EU and are regulated in Council Directive 2000/29/EC (Annex IAI) (as
non-European Endocronartium spp.) as harmful organisms whose introduction into the EU is banned.
These three fungi are autoecious rusts completing their life cycle on Pinus spp. C. harknessii is known
as the western gall rust or pine-pine gall rust in North America (Canada, the USA and Mexico).
C. kurilense and C. sahoanum are reported from Russia (North Kuril Islands) and Japan. The
pathogens could enter the EU via host plants for planting and cut branches. The pathogens could
establish in the EU, as climatic conditions are favourable and Pinus spp. are common. The pathogens
would be able to spread following establishment by movement of host plants for planting and cut
branches, as well as natural spread. Should these pathogens be introduced in the EU, impacts can be
expected on pine forests, plantations, ornamental trees and nurseries. The pathogens cause formation
of stem galls, which kill young trees and result in stem defect in older trees. The main knowledge gap
concerns the limited available information on C. kurilense and C. sahoanum compared to C. harknessii.
The criteria assessed by the Panel for consideration of C. harknessii, C. kurilense and C. sahoanum as
potential quarantine pests are met, whilst, for regulated non-quarantine pests, the criterion on the
pest presence in the EU is not met