Phytochemical analysis and larvicidal bio-efficacy of <i>Camellia sinensis</i> (L.) Kuntze leaf ethanol extracts against <i>Aedes aegypti</i> L.

The increasing resistance of Aedes aegypti to conventional chemical insecticides has intensified the search for eco-friendly alternatives in mosquito control. This study explores the larvicidal and developmental effects of Camellia sinensis (green tea) leaf extracts on Ae. aegypti, a major vector of dengue, Zika, and chikungunya viruses. Early 4th instar larvae of Ae. aegypti were treated with C. sinensis leaf ethanol extract (Cs-LEE) under controlled laboratory conditions. Key parameters, including larval and pupal mortality, developmental period, and adult emergence, were recorded. Results revealed a dose-dependent increase in larval and pupal mortality, significant delays in development, and reduced adult emergence in treated groups. Larval and pupal mortality was observed to be highest at 400 mg/L, 24.8% and 36.8% respectively. Development period of larvae and pupae increased to 5.57 days and 5.34 days at 400 mg/L. Similarly, adult emergence reduced to approximately 38% at 400 mg/L. Phytochemical screening confirmed the presence of bioactive substances such as catechins, alkaloids, and flavonoids, which are known to disrupt hormonal balance and interfere with enzymatic processes in insects. These findings highlight the potential of Cs-LEE as natural larvicidal agents. Their biodegradability, low toxicity to non-target organisms, and availability make them promising candidates for Integrated vector management (IVM) programs. Further research and field validation are necessary to develop safe, cost-effective botanical formulations for large-scale mosquito control.