EN
An invasive East Asian rust fungus Melampsoridium hiratsukanum, obligate biotroph belonging to Pucciniastraceae, Pucciniales (Basidiomycota) is found widely spread on leaves of Alnus incana in eastern, central and southern parts of Lithuania. On Alnus glutinosa this fungus is rare, sometimes occurring with an alder leaf pest, a microscopic eriophyid gall mite Acalitus brevitarsus. Information on the distribution patterns, ecological and morphological characters of this neomycete is given.