​This exercise can be used to stimulate the investigative nature of your students as they use forensic plant pathology techniques with powdery mildew chasmothecia (the sexual stage of powdery mildew fungi) to prove their innocence in a mock murder investigation. The exercise is suitable for grades 7 -12 and does not require the purchase or maintenance of special cultures, since chasmothecia produced by powdery mildew fungi are easy to find on plants in nature. Dissecting and compound microscopes are required.