| abstract | Three new gamasid mite species belonging to the genus Macronyssus Kolenati, 1858 (Acari: Macronyssidae), namely Macronyssus sibiricus n.sp., Macronyssus stanyukovichi n.sp. and Macronyssus tigirecus n.sp., are described (females only; males, protonymphs, and larvae remain unknown). All species are known from Western Siberia and belong to the Siberian-Far Eastern bat ectoparasite fauna complex. The parasite hosts are the eastern water bat Myotis petax Hollister, 1912, and Hildendorfʼs tube-nosed bat Murina hilgendorfi Peters, 1880 (Chiroptera: Vespertilionidae). An identification key for females of the gneus Macronyssus Kolenati, 1858, in the boreal Palearctic region is presented. |