From 2012 until 2014, surveys and frequent visiting the orchards of Hamedan province, west of Iran, have provided strong evidence for the existence of a mycoparasite. The olive green to dark brown velvet colonies, which were observed on infected fruit with Taphrina pruni, Pocket Plum gall, were collected. Morphological characteristics were investigated on Synthetic Nutrient Agar medium. A portion of the translation elongation factor 1-α gene was amplified by using the EF1-526-F and EF1-156-R primers and then sequenced. A mycoparasitic ability was performed by spraying a conidial suspension of Taphrina pruni (1 × 10 5 spores/mL) and sterile water on leaves. Symptoms appeared in 4–5 days of post-inoculation. The leaves were examined by a light microscope and a scanning electron microscope, and the results of examinations revealed that Cladosporium delicatulum, which had never been reported as a mycoparasite, was in Taphrina pruni.
