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...