ABSTRACT. The larvae and adults of Belgica antarctica were studied in an attempt to identify the mechanism of low temperature adaptation that enables this species to survive in the Antarctic. Larvae are freezing-tolerant during the austral summer and elaborate a complex of cryoprotectants including erythritol, glucose, sucrose and trehalose. Adults are freezing-susceptible and lack adequate quantities of cryoprotectants. Maintenance on artificial diets indicated that cryoprotectant profiles have food-source and temperature-dependent components. In addition, direct utilization of dietary cryoprotectants is suggested.