squashes (including pumpkins), luffas, melons and watermelons. [ edit ] Powdery mildew in lilacs Microsphaera syringae is a fungus that can cause powdery mildew in lilac . [ 13 ] [ edit ] Powdery mildew in strawberry Podosphaera aphanis is the cause of powdery mildew in strawberries and other Rosaceae like