Swarms of mayflies are pictured in Szentendre, Hungary on Sept. 1, 2024. (Photo: Xinhua)
Swarms of mayflies are pictured in Szentendre, Hungary on Sept. 1, 2024. (Photo: Xinhua)
Swarms of mayflies are pictured in Szentendre, Hungary on Sept. 1, 2024. (Photo: Xinhua)
Swarms of mayflies are pictured in Szentendre, Hungary on Sept. 1, 2024. (Photo: Xinhua)