First report of powdery mildew caused by Neoerysiphe galeopsidis on Lamium purpureum in Korea.
Lamium purpureum (Lamiaceae), known as red dead-nettle, is native to Europe and Asia Minor. It has been widely naturalized in East Asia including Korea, where it is considered an invasive species. In May 2018, several hundred plants of red dead-nettle were found heavily infected with a powdery mildew in Gongju, Korea Republic. Symptoms first appeared as thin white colonies, which subsequently developed into abundant hyphal growth on both sides of the leaves. The causal pathogen was isolated and identified as Neoerysiphe galeopsidis based on morphological, molecular and pathogenicity analyses. This is thought to be the first report of powdery mildew caused by N. galeopsidis on L. purpureum in Korea Republic.