Thermal influence on development and morphological traits of Aedes aegypti in central India and its relevance to climate change.

BACKGROUND

The geographic expansion of Aedes aegypti, an arboviral disease vector of global importance, is driven by urbanization, global travel, and climate change. Temperature significantly impacts the life cycle, distribution, and vectorial capacity of disease vectors. This study investigates the effects of temperature on the developmental biology, survival, reproductive traits, and wing morphometry of Ae. aegypti populations from central India (Bhopal, Madhya Pradesh).

METHODS

Larvae collected from the field were reared at controlled temperatures, on the basis of the historical and projected temperature changes, ranging from 10 ℃ to 40 ℃. Aedes stage-specific developmental times and survivorship rates were determined and compared. The right wings of male and female mosquitoes reared at 20 °C, 26 °C, and 32 °C were used for morphometric analysis on the basis of the digitized coordinates of 18 landmarks on the wing veins.

RESULTS

Higher temperature (32 °C) significantly accelerated life cycle completion, whereas 37 ℃ led to larval survival but high pupal mortality. In contrast, moderate temperatures (26 °C) optimized survival, reproductive output, and extended oviposition periods. Life table analysis revealed that elevated temperatures, particularly at 32 ℃, increased the intrinsic rate of population growth (r) and shortened generation times, indicating faster population turnover under warmer conditions. However, this rapid life cycle presents trade-offs, including lower survival and reproductive success, which could significantly impact vector population dynamics in the context of climate-driven temperature fluctuations. Wing morphometric analysis further revealed that mosquitoes reared at 32 °C and 26 °C had significantly smaller wings compared with those reared at 20 °C. Although smaller wings may limit dispersal capacity, previous studies suggest a possible link with increased host-seeking and enhanced vectorial potential at 32 °C.

CONCLUSIONS

This study highlights that Ae. aegypti populations from Central India exhibit thermal tolerance and developmental plasticity under elevated temperatures, suggesting their potential to thrive in warm climates. Rapid development and smaller wing size at higher temperatures may influence survival, fecundity, and biting behavior. Such traits can enhance disease transmission risks by supporting more frequent human-vector contact and sustaining mosquito populations in broader geographic areas.