1a) Survival after pupal heat-stress
When focusing on a single hardening temperature (36°C) compared with non-hardened controls, we found that pupal survival probability was significantly affected by the interaction between hardening and heat-stress temperature (χ2(5) = 33.74, p<0.001; Figure 1a). Specifically, pupae heat-hardened at 36°C showed significantly improved survival at higher stress temperatures over non-hardened pupae. Between the 3 hardening temperatures of 34, 35 and 36°C, we found no effect of hardening temperature (χ2(2) = 2.040, p=0.361; Figure 1a) on individual survival at the pupal stress temperature of 40°C.