Strong tolerance to freezing is a major survival strategy in insects inhabiting central Yakutia (Sakha Republic, Russia), the coldest region on earth

Yakutia is a part of eastern Siberia, located in north-eastern Russia. The climate of this area is very harsh even by Siberian standards, and is characterized by the absolute temperature minimum, which is below −64.4 °C, and a long period of low temperatures reaching to a range between −47 and −55 °C. Despite such a severe climate, the fauna and flora of Yakutia present a considerably rich biodiversity, suggesting a high adaptation potential of the organisms in this area. In this study, 30 local species of insects belonging to Coleoptera, Diptera and Lepidoptera were selected to investigate cold adaptation. The identification of the cold adaptation strategy was based on the measurement of the insect body supercooling point (SCP) and hemolymph ice-nucleating activity. According to the data collected, there is a high incidence of freeze tolerant species among the insects found in Yakutsk area (Yakutsk, 62° latitude, 130° longitude): 93.3% of them were freeze tolerant, and only 6.7% were freeze avoiding. It is suggested that the evolution of cold hardiness in this region preferably develops for the selection of the strong freeze tolerance that allow the insects to survive extreme cold conditions.