The effect of stage-specific heatwaves on Aedes albopictus (Diptera: Culicidae) survival and development

Ectotherms such as the tiger mosquito, Aedes albopictus (Skuse), are particularly sensitive to increasing temperatures due to climate change. While previous research has shown how Ae. albopictus is impacted by higher constant temperatures, less is known about how this species will respond to heatwaves-short time periods with maximum temperatures above normal. Due to mosquitoes' short generation time, heatwaves may occur during only one life stage, each of which differs in habitat, morphology, and thermal tolerance. In this study, we exposed mosquitoes to a five-day heatwave in the lab at the egg, larval, or adult stage and measured development and survival. Additionally, we had one group undergo heatwave conditions throughout all life stages to distinguish the effects of prolonged heat exposure and short-term, stage-specific heatwaves. We found that constant heatwave exposure reduced hatching success and delayed hatching in surviving eggs after the initial five-day treatment, increased female development rate, and decreased pupal and adult survival compared to controls. However, heatwaves at a single life stage did not significantly alter development rates or survival apart from adult survival, which was reduced. Our results suggest that while the juvenile stages of Ae. albopictus show resilience to short, stage-specific heatwaves, longer heatwaves occurring across multiple stages can significantly reduce survival, with implications for population dynamics under future climate scenarios. This is particularly important due to the ability of Ae. albopictus to vector many viruses including chikungunya and dengue.