Abstract
During September-October 2017, powdery mildew symptoms were observed on both surfaces of leaves of Chenopodium ambrosioides in Abbottabad, Malakand, and Upper Dir districts of Pakistan. The causal agent was identified as Erysiphe betae, based on its asexual morphology and chasmothecia, and its identity was confirmed by molecular data. This is the first Pakistani report of Erysiphe betae on this host.