Figure 1: Proportion of surviving individuals after a 4-hour heat stress. Focal individuals were subjected to a pre-stress ‘hardening’ treatment for 1-hour immediately prior to temperature stress. a) D. virilis individuals of unknown sex were heated during the pupal stage and subjected to a range of stressful temperatures. A range of hardening temperatures were also used to examine the hardening response. Note that the 34 and 35°C hardening temperatures were not measured at 37 and 38°C temperature stress.b) Male and female D. virilis were heated during the adult stage 7 days post-emergence, and subjected to two stress temperatures (23°C: benign, 38°C, stress). Error bars represent 95% confidence intervals.