Evaluation of Larvicidal Potential of Nepeta cataria and Cymbopogon nardus Essential Oils Against Aedes aegypti.

Mosquito-borne diseases remain one of the greatest challenges to global public health, with Aedes aegypti (A. aegypti) serving as a primary vector of arboviruses such as dengue, chikungunya, yellow fever, and Zika. Reliance on synthetic insecticides for larval control has contributed to ecological concerns, human health risks, and the emergence of resistance in mosquito populations. These issues highlight the urgent need for safer, sustainable, and environmentally compatible alternatives. The present study investigated the larvicidal efficacy of essential oils extracted from locally grown plants. Cymbopogon nardus (C. nardus) (citronella) and Nepeta cataria (N. cataria) (catnip) as potential botanical substitutes in the scenario of changing climate. Fresh plant materials were authenticated, processed, and subjected to solvent extraction. The chemical composition of both oils was characterized using gas chromatography-mass spectrometry (GC-MS), which confirmed several phytoconstituents of biological importance, including citronellol, citronellal, geraniol, and nepetalactone isomers. Larvicidal bioassays were performed against A. aegypti using two stock concentrations (1 and 0.1%) at variable doses, with mortality monitored after 24, 48, and 72 h of exposure. Both essential oils demonstrated evident dose- and time-dependent mortality, with complete larval death observed at higher concentrations. Probit regression analysis provided effective LC50 and LC90 values, confirming the strong larvicidal activity of both extracts. Their use can not only reduce dependency on hazardous synthetic insecticides but also support the development of greener strategies within integrated mosquito management programs.