First report of Biscogniauxia mediterranea (De Not.) Kuntze on Celtis australis L. in Bulgaria

This is the first record for Bulgaria of Celtis australis as a new host of Biscogniauxia mediterraneа . Symptoms of the disease (presence of stroma on stems and branches) were found on dried trees in ‘Ayazmoto’ Park in Stara Zagora in the fall of 2024. The route survey conducted in the spring of 2025 showed that out of a total of 140 trees, 21 were completely dry, and 11 were partially dry. Half of the surveyed trees (70) were determined to be healthy. The detailed survey showed the presence of the black stroma characteristic of the genus Biscogniauxia on four dried trees. The results of laboratory analyses give us reason to confirm that the causative agent of European nettle wilt is B. mediterranea .