Origin: North America
First finding in Slovenia: not yet found in Slovenia
Pathways: transported with branches, wood and bark; spores secondary spread spontaneously.
Possible to identify: year-round
Habitat: This fungus affects primarily Persian and Eastern black walnut (Juglans regia and J. nigra).
Status in Slovenia: The fungus is quickly spreading in northern Italy and it is expected to spread also to Slovenia.
Similar species: walnut trees are not affected by fungi with similar symptoms.