Five 1 l cylindrical plastic cups filled with 800 ml deionised water and 40 larvae each were set up for every temperature treatment. Larval rearing temperatures were set to 0, 5, 10, 12, 14, 15, 17, 19, 20, 23, 25, 26, 27, 28, 29 and 31 °C and photoperiod to 16:8 h light: dark without crepuscular transitions. Larvae were fed with 10 mg TetraMin (Tetra, Melle, Germany) per larva in seven portions .