Effect of environmental conditions on the wing morphometric variation in Aedes aegypti (Diptera: Culicidae) in India

Aedes aegypti an efficient vector of different arboviral diseases, is a major concern for public health globally. Originating from Africa, this vector has now invaded most of the parts of the world, which shows its thriving adaptability against diverse ecological conditions. In India too, Ae. aegypti has been found almost everywhere and along with Ae. albopictus, it contributed more than 0.2 million cases of dengue in the year 2022. Due to heterogeneous environmental settings in India, this vector has shown various intraspecific variations including its behavioral, genetic, and physiological characteristics. Thus, the present study hypothesized that there will be some differences in wing morphometrics across the country for this species. Considering this, we have sampled adults and immatures of Ae. aegypti from 11 distinct locations, representing six varied climatic regions of India. The immatures were reared to adult and the right wing was used to score the morphometric variations. A significant variation in wing size and shape was observed. The Himalayan region (Srinagar CS: 1.92 {+/-} 0.08 mm) supports the shortest (CS: 2.04 {+/-} 0.09 mm) wing size mosquitoes while the Deccan Peninsular region (Nagpur CS: 4.48 {+/-} 0.06 mm) exhibits the largest (CS: 4.46 {+/-} 0.10 mm) wing size mosquito. After excluding the allometric effect, the semi-desert region (Kota) showed the greatest wide variety of wing shapes corresponding to a larger morphospace in CVA analysis. In addition, region-wise wing size was found positively correlated with temperature (64%) and altitude (82%) but no directional trend was detected for wing shape characteristics. Conclusively, the study suggests the existence of varied population structures of Ae. aegypti in India based on wing morphometric analysis. This finding will be helpful towards focused actions and early measures to reduce the impact of these diseases carrying mosquitoes on public health.