The Caucasian subgenus Plumiger Horváth, 1927 of the halticine genus Myrmecophyes Fieber, 1870 is revised. A key, updated diagnoses, and data on distribution are given for the subgenus and its four species, including M.tomi sp. n. (Georgia and Dagestan), and the previously unknown male of M.armeniacus Drapolyuk, 1989. Illustrations of the male and female genitalia, photographs of the dorsal habitus, and SEM micrographs of selected structures are provided for all species of the subgenus.
Keywords: Alpine meadows; Caucasus; diagnosis; female genitalia; key to species; male genitalia; systematics.