Occurrence of the fungi from the genus Ampelomyces – hyperparasites of powdery mildews (Erysiphales) infesting trees and bushes in the municipal environment

The studies refer to the phenomenon of hyperparasitism in the municipal environment. The paper presents the occurrence of fungi of the genus Ampelomyces on Erysiphales – important group of phytopathogenic fungi. For the first time in Poland analyzed degree of infestation of Erysiphales mycelium by Ampelomyces and effect of the hyperparsites on the degree of infestation plants by Erysiphales. The high participation of the Ampelomyces was noted in each year of the study. Substantial differences were noted in the occurrence of Ampelomyces depending on the developmental stage of the host fungi and considerable differences in the prevalence of the hyperparasites on particular Erysiphales species. In all cases examined, the mean index of infestation of host plants by Erysiphales was higher than the mean degree of infestation of powdery mildew mycelium by Ampelomyces. The results indicate that under natural conditions they do not play any significant role in the reduction of the degree of infestation of host plants by Erysiphales and do not disturb drastically their life cycle.