Eggs were incubated for ten exposure periods (0, 6, 12, 18 h and 1, 2, 3, 4, 7, 14 days) at 5 °C, 0 °C, -5 °C and - 9 °C. Twenty eggs were placed on a coffee filter paper (diameter 2 cm) soaked with 200 μl deionised water and placed in a 100 ml plastic beaker. Five cups per temperature and exposure length were set up (4000 eggs in total). Larval hatch was stimulated by filling the cups with 80 ml deionised water and bringing them to 25 °C. Hatched larvae were counted on three consecutive days after hatching stimulus. Only larvae completely detached from the eggshell were counted and included when calculating the mean hatch success. Hatch success was arcsine transformed, and logistic or exponential regressions were selected based on AIC values calculated in Past 3 . Based on the resulting functions, minimal hatch success was calculated.