The thermal stress response of Aedes aegypti and Aedes albopictus when exposed to rapid temperature changes

Autocidal mosquito control approaches are based on rearing mosquitoes in consistent and stable laboratory conditions; however, when adult mosquitoes are released in field settings, they have to rapidly respond to changes in temperature and thermal stress. To examine the effect of thermal stress on mosquitoes, Aedes aegypti and Aedes albopictus larvae were reared at either 22 °C (R22) or 28 °C (R28) and emerged adults were subsequently exposed to temperatures of 22 °C (E22), 28 °C (E28), 32 °C (E32), or 38 °C (E38). After the mosquitoes were subjected to these altered temperature profiles, we examined for effects on adult survivorship, respiration rates, and heat shock protein (HSP) expression. Reduced adult survivorship was observed when the rearing temperature was different than the adult exposure temperature. Respiration rates as a measure of thermal stress varied with rearing conditions and exposure temperatures, with notable declines observed as exposure temperatures increased. HSP gene expression was generally upregulated in response to thermal stress, with specific patterns differing by species and rearing conditions. Wing length measurements revealed no significant developmental differences across rearing temperatures, except for Ae. aegypti females. These findings highlight the impact of temperature on mosquito physiology and the potential impacts of rearing and environmental temperatures on the effectiveness of autocidal approaches for mosquito and disease control.