Thermal stress can affect the field performance of sterile males used in the sterile insect technique (SIT). We tested whether adding autoclaved Enterobacter as a dietary supplement improves thermal tolerance in sterile Vienna 8 genetic sexing strain males of Ceratitis capitata. Larval and adult diets were supplemented with autoclaved Enterobacter, and critical thermal limits – critical thermal minimum (CTmin), critical thermal maximum (CTmax), and chill-coma recovery time (CCRT) – were measured. Enterobacter supplementation affected neither CTmin nor CTmax. In contrast, CCRT was strongly influenced by larval diet: sterile males reared on the standard diet recovered faster than those reared on the Enterobacter-supplemented diet. Wild males showed a lower CTmax but a much faster CCRT than sterile males. Overall, Enterobacter supplementation did not improve thermal limits but affected chill-coma recovery, highlighting the importance of characterising the thermal profile of sterile males before release and the complex interplay between food quality, physiology, and mass-rearing in the successful application of SIT.
