Leveillula compositarum

About

Phyllactinia taurica is a species complex of powdery mildews in the family Erysiphaceae. It is found across the world, where it affects a vast array of different plant families. Phyllactinia taurica is one of the most polyphagous powdery mildew species in the world, although attempts have been made to split it in the past and it may be a complex of many cryptic species on different hosts.

Summary from Wikipedia