Platanus species are widely planted as amenity trees in temperate regions worldwide for their ability to survive in harsh urban streets and soil environments (Sanusi & Lvesley, 2020;Wood & Esaian, 2020).Belonging to the family Platanaceae, they are broad-leaved and deciduous trees. Platanus occidentalis L., commonly known as the American sycamore or American planetree, is a popular street tree in Korea (Woo, 2006). Several diseases and pests of this species are known, including anthracnose caused by Apiognomonia veneta, powdery mildew caused by Erysiphe platani, Hyphantria cunea, fall webworm and Corythucha ciliata, sycamore lace bug (La et al., 2009(La et al., , 2013.Mycosphaerella leaf spot, caused by Mycosphaerella platanifolia, appears in Platanus species including P. occidentalis (Filer et al., 1977;La et al., 2009). Taxonomic reassessments have been performed on the genus Mycosphaerella (Braun & Crous, 2006;Crous & Corlett, 1998). A fungus causing black leaf spot on P. orientalis in Australia was thus identified as Pseudocercospora platanigena (= Stigmina platani) (Carnegie et al., 2021). The fungal pathogen attacking P. occidentalis in Korea is currently known as