Cold hardiness of some Alpine Collembola

1 Individual supercooling points ranged from ‐2 to ‐44°C for six species of springtails, five species from the Swiss Alps and one from lowland Britain. Individuals of Isotomurus alticola (Carl) and Isotoma viridis Bourlet without gut contents had substantially lower supercooling points than those containing food material. 2 Juveniles were more cold resistant than adults in both I.alticola and Isotoma hiemalis Schött, both with respect to supercooling point and to their survival at prolonged subzero temperatures. 3 Temperature and acclimation time affected the degree of supercooling of four of the Alpine species especially I.hiemalis. 4 Duration of culture period had no consistent influence on the supercooling potential of all the species. 5 Tests for glycerol in the body fluids of the five Alpine springtails were negative, but the presence of a sugar, probably glucose, together with a five carbon polyhydric alcohol was indicated by chromatography.