Most cold-tolerant insect (terrestrial)

The most cold-tolerant insect is the larva of the red flat bark beetle (Cucujus clavipes puniceus), native to Alaska, USA. Some populations in the wild state have been seen to remain unfrozen at temperatures as low as -80°C (-112°F). Moreover, under laboratory conditions these beetle larvae were found to survive unharmed at temperatures as low as -150°C (-238°F). They achieve this extraordinary feat by not only producing antifreeze proteins that protect them down to as low as -20°C (-4°F) but also dehydrating and increasing their internal glycerol concentration, to such an extent that their body fluids turn into a viscous glass at -58°C (-72.4°F). This extraordinary vitrification process then protects them all the way down to -150C.

Prior to the above-described extreme cold tolerance exhibited by the larvae of the red flat bark beetle, the assumed record holder for most cold-tolerant insect was the woolly bear caterpillar of the Arctic woolly bear moth (Gynaephora groenlandica). Native to Canada's high Arctic zone, as well as to Greenland and to Russia's Wrangel Island, its caterpillar spends up to 10 months of the year frozen solid at temperatures that drop as low as -50°C (-58°F).