Moulting reduces freeze susceptibility in the Antarctic mite Alaskozetes antarcticus (Michael)

The effect of moulting on the cold hardiness of the oribatid mite Alaskozetes antarcticus (Michael) is investigated. Non moulting animals show clear seasonal patterns of cold hardiness with high supercooling points (SCPs) at the peak of summer and an increasing proportion of low SCPs with declining environmental temperatures. By contrast, both field-fresh and laboratory acclimated (5 °C) mites in the moult state are consistently found to have low SCPs regardless of environmental temperature.