[4 new species of blackflies (Diptera: Simuliidae) from Central Asia, Siberia and the Far East].

Four new species of blackflies (Diptera: Simuliidae) are described. Helodon rezidentsii Yankovsky, sp. n., Khabarovsk Territory, differs from all known species of the genus with morphology of eyes consisting only of microommatidii in male; from related species H. kamtshaticus (Rubzov, 1940) with large triangular posteromedial lobes of branches of genital fork in female; with number of rays of primary fan of premandibles (20-22, when in H. kamtshaticus 30-32) in larva. Helodon submulticaulis Yankovsky, sp. n., Transbaikalia, differs from related species H. multicaulis (Popov, 1968) with number of rays of primary fan of mandibles (36-40, when in H. multicaulis 26-28), narrow anterior branches of anal sclerite, number of rows of hooks in posterior attachment organ (88-92, when in H. multicaulis 78-80) in larva; with morphology of respiratory organ, consisting of 5-8 lobes bearing 40-60 tune filaments (in H. multicaulis 3-4 lobes bearing more than 150 filaments) in pupa. Sch. samarkandica Yankovsky, sp. n., Uzbekistan, differs from related species Sch. pseudopusilla Rubzov, 1956 with 3 (not 2 as in Sch. pseudopusilla) hooks in parameres, bifurcated lateral branches of X sternite, long projection of gonostyles in male. Schoenbaueria ivdelensis Yankovsky, sp. n., Middle Ural, differs from related species Sch. rangiferina (Rubzov, 1956) with prolonged gonostyles bearing narrow projection in male; with number of rays of secondary fan of premandibles (20-28, when in Sch. rangiferina 44-48), deep ventral groove of cephalic capsule, number of rows of hooks in posterior attachment organ (80-82, when in Sch. rangiferina 70-72) in larva; with morphology of respiratory organ (very long stems of 2 and 3 pairs of filaments) in pupa.