Effect of Humidity and Monsoon Shifts on Mosquito Breeding Genetics and Survival Traits

Climate variability—particularly fluctuations in humidity and shifts in monsoon onset, duration, and intensity—plays a critical role in shaping the ecology, physiology, and genetic adaptability of Culex quinquefasciatus, a significant vector of lymphatic filariasis and West Nile virus. Changing monsoon patterns and prolonged humid periods create new breeding habitats, influence larval development cycles, and potentially alter genetic structures within mosquito populations. This study investigates how humidity gradients and monsoon variability affect breeding dynamics, survival traits, and population genetics of C. quinquefasciatus across tropical and semi-tropical ecosystems. Mosquito samples were collected across pre-monsoon, monsoon, and post-monsoon seasons from four ecological zones. Climatic parameters, including relative humidity and rainfall anomalies, were combined with molecular analyses using mitochondrial COI markers, microsatellites, and climate-responsive genes such as HSP70. Statistical methods, including AMOVA, regression modelling, and structure analysis, were applied to identify genetic differentiation and climate-driven selection pressures. Results show that high humidity (>80%) significantly enhances egg hatching, larval survival, and adult longevity, while monsoon irregularities produce short-term genetic bottlenecks followed by rapid adaptive recovery. Distinct seasonal genetic clusters suggest ongoing microevolutionary responses to climatic stress. These findings underscore the potential expansion of vector populations under future climate scenarios, increasing the risk of filariasis and West Nile virus transmission. Understanding climate–genetic interactions in C. quinquefasciatus is essential for designing predictive vector surveillance and targeted control interventions.