First report of Pseudomonas syringae pv. aesculi in Finland
The NPPO of Finland recently informed the EPPO Secretariat of the first finding of Pseudomonas syringae pv. aesculi (formerly EPPO Alert List) on its territory. Arborists of the city of Helsinki notified to the NPPO the occurrence of dying horse chestnut trees (Aesculus hippocastaneum) in the Tokoinranta park in summer 2015 and in the Sibeliuspuisto park in summer 2016. In both places, bleeding symptoms on the trunks could be observed. Wood and bark samples were taken to the laboratory for diagnosis (isolation, PCR, sequencing). Results confirmed the presence of Pseudomonas syringae pv. aesculi in diseased trees. The origin of the bacterium and its pathway of introduction into Finland are unknown. This is the first time that Pseudomonas syringae pv. aesculi is reported from Finland. No official measures have been taken but all symptomatic trees have been cut down by the construction service of the city of Helsinki.
The official pest status of Pseudomonas syringae pv. aesculi in Finland is officially declared as: Present, only in some areas.
NPPO of Finland (2016-07).