Answer: oidia

AnswerCrossword Clue
oidiapowdery mildew especially of grapes caused by an oidium
oidiaOIDIUM, a type of fungus (any of the major group of lower plants)
oidiaone of the conidia that are borne in chains by certain fungi
oidia(in certain fungi) a thin-walled spore derived from the fragmentation of a hypha into its component cells