Twenty-one species of the genus Istrianis are recognized as valid in the world fauna, 11 of which are described as new: I. pseudomyricariella sp. nov. (Greece, Kyrgyzstan, Tadzhikistan), I. nilssoni sp. nov. (Greece), I. kravchenkoi sp. nov. (Palestine), I. sattleri sp. nov. (Pakistan), I. armatus sp. nov. (Yemen), I. lvovskyi sp. nov. (Mongolia), I. sruogai sp. nov. (Turkmenistan, Tadzhikistan...