The Syrphidae constitute one of the most representative families in the sub-order of Diptera Brachycera, the fauna of Siberia numbering about 600-700 species (the whole of the U.S.S.R. numbering about 1100). They occur practically everywhere and are of considerable economic importance, chiefly as pollinators of Angiosperm plants. Moreover the larvae of many species are predators of aphids and often reduce their numbers considerably, which has a noticeable useful effect. Only a small number of species are plant pests: especially bulb plants (onion, tulip, hyacinth, etc.) are damaged through boring in the bulbs. The usefulness of the Syrphidae as a whole, however, greatly exceeds the nocivity of these few harmful species. Recently, as a result of the growing concern about Nature Conservancy, numerous papers have been published on the part played by the Syrphidae as pollinators and as entomophagous insects. For a long time the identification of Syrphidae had to be effected by means of obsolete keys by A.A. Stackelberg (1930) and P. Sack (1932-1935). For the identification of the Syrphidae of the Far East Shiraki’s book (1930) was used. In 1970 at last appeared “Keys for the identification of insects of the European part of the U.S.S.R.” in which A.A. Stackelberg treated the Syrphidae. We wish to stress the great merits of A.A. Stackelberg as a specialist of the Palaearctic Syrphidae, especially those of the Leningrad district, the Far East, Tadzhikistan and the Caucasus. He published many papers on the systematics of numerous genera of the Palaearctic region (Sphegina, Neoascia, Orthoneura, Eumerus, Mallota, Brachypalpus, Xylota, etc.), in which some 200 new species were described. Most unfortunately, however, AA Stackelberg was not allowed the time for a fundamental treatment of the Syrphid fauna of Siberia, a gap which we are now intending to fill.