First record of Erysiphe pulchra in China on a new host species.

Erysiphe pulchra (Erysiphe sect. Microsphaera) was identified on Cornus kousa subsp. chinensis (equivalent to Dendrobenthamia japonica var. chinensis). This is the first record of this species in China, and C. kousa subsp. chinensis is a new host plant for E. pulchra. The Chinese specimen is described, illustrated, and discussed and its affinity has been confirmed using molecular methods.