Origin: Far East

First finding in Slovenia: before 2010

Pathways: likely transported with fruits; secondary spontaneous spreading

Possible to identify: June-October

Habitat: Common on Alnus incana, more rarely on Alnus glutinosa.

Status in Slovenia: Currently spreading, the severity of the infection differs from year to year, depending on the weather (high humidity increases infection pressure).

Similar species: Melampsoridium alni, M. betulinum & M. carpini. 

Source: Terenski priročnik za prepoznavanje tujerodnih vrst v gozdovih (Fieldguide for the identification of alien species in forests)