Supercooling points of insects and mites on the Antarctic Peninsula

1. Mean supercooling points of eleven species of arthropods (three Collembola, seven Acari and one Diptera) ranged from ‐6.2 to ‐9.4°C (high group), and from ‐17.7 to ‐31.0°C (low group). The majority of individuals in the high group had food in their gut systems. 2. Freezing was lethal to all species examined except larval Belgica antarctica Jacobs (Chironomidae). 3. Glucose, glycerol and mannitol were found in low concentrations in extracts of Ctyptopygus antarcticus Willem (Collembola) and larvae of B. antarcrica; it is udikely that these substances had a major effect on the supercooling of either species. 4. Two Collembola species possessed significantly (P< 0.05) lower supercooling points at locations on the Antarctic Pensinsula than at Signy Island, South Orkney Islands. The converse was observed for two species of Acari. 5. It is suggested that whilst gross climatic and also micro‐habitat conditions may influence the cold hardiness of such arthropods, especially seasonally, their full supercooling ability is rarely tested.