The paper "How to assess Drosophila cold tolerance: chill coma temperature and lower lethal temperature are the best predictors of cold distribution limits" is now avaliable online.
Five metrics of cold tolerance were measured for 14 Drosophila species to determine which metrics most strongly correlate with geographic distribution. Measures of chill coma onset temperature, lethal temperature and lethal time at low temperature proved to be the best predictors to describe the variation in realized latitudinal distributions and estimated environmental cold exposure. Measures of chill coma recovery time also correlated significantly with estimated minimum temperature, while the supercooling point did not.
Considering the findings of the present study, data from previous studies and the logistical constraints of each measure of cold tolerance, we conclude that chill coma onset temperature and lethal temperature are superior measures when estimating the ecologically relevant cold tolerance of drosophilids. Of these two traits, chill coma onset temperature requires less equipment, time and animals and thereby presents a relatively fast, simple and dynamic measure of cold tolerance.