Night warming on hot days produces novel impacts on development, survival and reproduction in a small arthropod

1. An asymmetric increase of nighttime temperatures on hot days is one of the main features of global climate change. But the biological effects of an increased nighttime temperature combined with high daytime temperature are unclear. 2. We used six thermal regimens to simulate nighttime temperatures on hot days and investigated the effects of night warming on life history traits of the English grain aphid Sitobion avenae. Experimental temperatures fluctuated in continuous diurnal cycles, increasing from 27 °C to a maximum 35 °C and then declining to 27 °C gradually before further dropping to different minima (13, 16, 19, 21, 23 or 25 °C) representing nighttime temperatures. 3. When compared to expectations based on constant temperatures, night warming raised the optimum temperature for development by 3 °C, in contrast to results from experiments where temperature variability was altered symmetrically or in a parallel manner. Night warming also reduced aphid survival under heat from 75%...

1. 热日夜间气温的不对称升高是全球气候变化的主要特征之一。然而，夜间升温叠加日间高温所产生的生物学效应尚不明确。2. 本研究采用6种热调控方案模拟热日夜间气温，探究了夜间升温对麦长管蚜（Sitobion avenae）生活史性状的影响。实验温度以连续昼夜周期波动：从27℃升至最高35℃，随后逐渐回落至27℃，再进一步降至不同的最低温度（13、16、19、21、23或25℃）以代表夜间气温。3. 与基于恒温的预期结果相比，夜间升温使发育最适温度升高了3℃，这与温度变异呈对称或平行改变的实验结果截然相反。此外，夜间升温还将蚜虫的高温存活率从75%……