On the reasons for a sharp curve in the western boundary of the ranges of some eastern dragonfly species in the north of western Siberia

Recently, the authors discovered the eastern Siberian spp., Coenagrion hylas (Trybom), Somatochlora graeseri Sel. and Leucorrhinia orientalis Sel. in the N of the U rals, i.e. almost 1500 km W of their range boundary as proposed earlier. This phenomenon can be explained by the ease with which dragonflies disperse on the forest-tundra open space, rich in surface waters.