First report of the rust fungus Uromyces plumbarius in Europe

The rust fungus Uromyces plumbarius Peck was reported in Europe for the first time on Oenothera lindheimeri (Engelm. & A. Gray) W.L. Wagner & Hoch (Lindheimer’s beeblossom), a highly popular ornamental plant widely cultivated since the 2000s. The fungus was found in 11 locations across France and two locations in the Netherlands. These multiple findings, which occurred between 2020 and 2023, were initially shared among professional and amateur plant pathologists via the social media platforms Twitter and later Bluesky. This collaborative exchange allowed for a more comprehensive first report than usual, already indicating a relatively broad geographic distribution. The identification of U. plumbarius was based on an analysis of morphological characteristics and 28S rDNA sequences, conducted at the BIOGER unit in Palaiseau, outside the unit’s usual focus on pathogens of major field crops. The pathogenicity was confirmed through reinoculation using fresh urediniospores, carried out at the IAM unit in Nancy. This represents the first record of U. plumbarius outside its native range in North America. Its widespread distribution in France appears to result from rapid dissemination, likely facilitated by the plant trade between nursery gardeners. The discovery of U. plumbarius was accompanied by the detection of the hyperparasitic fungus Sphaerellopsis sp. and fungivorous larvae of Mycodiplosis sp.—two native, non-specific natural enemies which may play a role in limiting the impact of rust infections.

Reference : Suffert F, Meyer K, Laval V, Andrieux A, Slootweg E, Frey P. 2025. Uromyces plumbarius first reported on Oenothera lindheimeri in Europe with widespread distribution and association with two common natural enemies of rust fungi. European Journal of Plant Pathology, on line https://doi.org/10.1007/s10658-025-03109-x [free access pdf]