First report of powdery mildew caused by Podosphaera sp. on Phlox drummondii in Italy.
During the summer 2010 and the following autumn, symptoms of a new powdery mildew were observed on plants of Phlox drummondii growing in borders of private gardens located in Biella province (Piedmont, northern Italy). Symptoms of the disease are reported and the features of the fungal causal agent observed under microscope are described. The perfect stage of the microorganism was not observed. The pathogen was classified as Podosphaera sp. with ITS (Internal Transcribed Spacer) analysis. Finally, some strategies to prevent and to control this pathogen are given. This is the first report of Podosphaera on P. drummondii in Italy.