First report of Geosmithia morbida in France
The NPPO of France recently informed the EPPO Secretariat of the first finding of Geosmithia morbida (EPPO A2 List) on its territory. This fungus which is associated with the thousand cankers disease was detected in the vicinity of Lyon (Auvergne-Rhône-Alpes region) in a park on 3 symptomatic walnut (Juglans regia) trees. The identity of the fungus was confirmed in November 2022 by morphological and molecular methods. This detection was linked to surveys which have been carried out following the capture of the insect vector, Pityophthorus juglandis (Coleoptera: Curculionidae: Scolytinae, EPPO A2 List) in September 2022 near Lyon (EPPO RS 2022/232). After careful examination, it was found that attacked walnut trees also showed holes and galleries of P. juglandis, and that a few insect specimens were present. A specific survey for G. morbida and its vector will be carried out, including visual examination of host plants (Juglans, Pterocarya), sampling in the case of symptoms and inspections on sites which are more at risk. The source of this outbreak is under investigation.
The pest status of Geosmithia morbida in France is officially declared as: Transient, actionable, under eradication.
Sources
NPPO of France (2022-12).