Figure 2: Cumulative fertility of male D. virilis over time after a 4h heat-stress. Focal individuals were subjected to a pre-stress hardening treatment for 1h immediately prior to temperature stress. The age at heat-stress is represented using an arrow, and the life-stage of the individual is represented using grey (pupal) and white (adult) background. a) Individuals were heated during the pupal stage at either benign (23°C) or stressful (38°C) temperatures. Individuals were exposed to a 1h hardening treatment at 23°C (‘non-hardening’) or 36°C (‘hardening’) prior to heat-stress. Focal males were given a single group of virgin females at the first day post-eclosion. b) Individuals were heated during the adult stage at either benign (23°C) or stressful (35°C) temperatures. Individuals were exposed to a 1h hardening treatment at 23°C (‘non-hardening’) or 33°C (‘hardening’) prior to heat-stress. Focal males were given access to 2 groups of virgin females: one from days 1 to 6 post-heat, and another fresh set of virgin females from day 7 post-heat, to account for delayed sterility of males. Error bars represent 95% confidence intervals.