We report on one new species, Aceria asphodelinis n. sp., from inflorescences of Asphodeline taurica (Pall. ex Bieb.) Kunth (Xanthorrhoeaceae), one new combination, Paraphytoptus chondrillae () n. comb. (transferred from Aceria), from deformed inflorescences of Chondrilla juncea L. (Compositae), and six new records of eriophyine mites (Eriophyoidea, Eriophyidae, Eriophyinae) in southeast Crimea: Aceria peucedani () from flowers of Seseli tortuosum L. (Apiaceae), Aceria salviae () from inflorescences of Salvia tesquicola Klokov & Pobed. (Lamiaceae), Aceria erinea () and Aceria tristriata () from leaf galls of Juglans regia L. (Juglandaceae), Eriophyes calycobius () from buds of Crataegus monogyna Jacq. (Rosaceae), Eriophyes pyri () from parenchymatous leaf galls (“blisters”) of Pyrus communis L. (Rosaceae). Partial mitochondrial Cox1 sequences (1155 bp, 385 amino acids) of six Aceria and Eriophyes species are provided (GenBank accession numbers: MW691978–MW691983; MW851284). Aceria salviae, previously reported as a gall-former, was found to be vagrant, causing no visible damage to the host plant. Data from the literature suggests that it may be quite common for conspecific eriophyoids to differ in their ability to cause galls on closely related hosts. We provide several hypotheses that may explain this phenomenon and highlight the need for testing them via field experiments as well as molecular methods. We also advocate for broader usage of barcoding techniques in the taxonomy of Eriophyoidea and underline the importance of increasing the number of publicly available barcodes for various eriophyoid taxa.