Effects of regional climatic conditions on the wing morphometrics of the dengue vector Aedes aegypti (Diptera: Culicidae) in India

Aedes aegypti (Linnaeus, 1762), a major arboviral vector of global importance, demonstrates high adaptability across diverse environments. In India, Ae. aegypti is widespread across the country, thriving in highly diverse environmental conditions. Given its genetic, behavioral, and physiological variability, this study explores whether environmental factors also influence phenotypic traits such as wing morphology across the diverse climatic conditions of India. Right wings from 256 female Ae. aegypti specimens across 12 populations in five major climatic regions of India, viz. , Arid, Semi-Arid, Tropical Wet, and Dry, Mountain, and Humid Subtropical, were analyzed for morphometric variation. Significant differences in wing centroid size (CS) and shape were observed among both the populations and climatic regions. Arid region (3.95 ± 0.56) and Nagpur population (4.49 ± 0.31) exhibited the largest wings, while Mountain region (Srinagar population) showed the smallest (1.93 ± 0.11). Canonical Variate Analysis (CVA) revealed significant wing shape differences among both populations and regions, with the Semi-Arid region and Kota population showing distinct divergence. Cross-validated reclassification demonstrated high accuracy, with 79% of population-level and 90% of region-level comparisons exceeding 50%. Redundancy Analysis (RDA) showed that wing size was positively influenced by diurnal temperature range, root-soil moisture, and latitude, while precipitation and surface moisture had negative effects. Neighbor-Joining trees highlighted phenetic clustering influenced more by local environmental conditions than macroclimatic zones. Conclusively, this study highlights the role of environmental variation in shaping wing morphometry, providing insights into population differentiation and aiding region-specific vector control strategies.