The North American walnut pouch eriophyoid gall mite Aceria brachytarsus (Keifer, 1939) (Acariformes: Eriophyidae), which is trophically associated with host plants of the family Juglandaceae, has been recorded in Russia for the first time. The species was found in 2024 in Republic of Crimea and Donetsk People’s Republic, and in 2025 in Zaporozhye and Kherson regions on the leaves of common walnut Juglans regia L. Outside its native range, A. brachytarsus was first reported in Iran in 1990, with subsequent records in Europe dating back to the early 21st century. Currently, the species has been recorded in many European countries. It is likely that A. brachytarsus is already widespread in southern regions of Russia but has remained undetected by specialists until recently. The species is not considered an economically significant pest of walnut, but its participation in the formation of a multi-species complex of specialized phytophagous species can have a negative effect on the phytosanitary status of this valuable crop, including due to the synergistic effect.

Martynov V.V., Nikulina T.V., Gubin A.I.