Ypsolopha chazariella (Mann, 1866) (Lepidoptera: Ypsolophidae) is a European moth species known to feed on Tatar maple (Acer tataricum L.), a tree species naturally present in Europe. In 2009–2023, characteristic damage provisionally attributed to Y. chazariella was documented in botanical gardens in Novosibirsk, Krasnoyarsk (Russia, Siberia), suggesting the occurrence of a new pest. In 2024, significant damage was observed in an arboretum in Krasnoyarsk (Eastern Siberia) on the introduced A. tataricum and East Asian Acer ginnala Maxim. Two adult specimens of Y. chazariella were reared from larvae collected on both maple hosts and identified using genital morphology. Seven DNA barcodes (mitochondrial COI gene fragments) obtained for the specimens from Krasnoyarsk (6 specimens) and Novosibirsk (1) analyzed together with available DNA barcodes from Belarus and Finland showed low intraspecific divergence (0.7%). Among six haplotypes detected, two of them were formed solely by the Siberian specimens connected with the haplotypes recorded in Europe through two mutation steps. Genetic distance analyses revealed clear differentiation from closely related species (Y. dorsimaculella, Y. arizonella, and Y. rubrella) in the Barcode of Life Database (BOLD), with pairwise minimal distances between Y. chazariella and above-mentioned species ranging from 10.6% to 12.9%. A brief species essay was compiled, providing a note on the species biology, molecular genetics, present species range, and impact in ornamental plantings. Photographic documentation includes characteristic feeding damage and images of adult moths, along with detailed illustrations of male and female genitalia.