Possible ways of developing the fauna of the genus Cheilosia (Diptera, Syrphidae) in the Old World [Russian]

摘要

In northeastern Asia, the taxon Cheilosia is suggested to be of the early Eocene origin. This conclusion is made on the basis of analyzing the paleontological material of the genus with reference to ecological preferences of recent species. A hypothesis about the penetration of Cheilosia into northern Europe and North America through the Turgai and Beringian "bridges" existing in the middle Eocene. Favorable conditions for the genus are suggested to develop in the Neogene, when the intense exchange of faunas between Europe and Asia took place, and the diversity of landscapes decreased. The current pattern of distribution of Cheilosia has resulted from intense migrations of faunas during periods of glaciation and interglacial warming.