Comparative efficacy assessment of crude and commercial Cymbopogon citratus essential oil against Aedes aegypti L.

Abstract Every year, millions of people are affected by mosquito-borne illnesses, which pose a serious danger to world health. To stop the spread of these diseases, it is essential to manage the population of their main vector. Growing resistance of Aedes aegypti to traditional insecticides calls for safer and more environmental-friendly solutions. This study compares the toxicity of commercial and crude extracted essential oil (by steam distillation) of Cymbopogon citratus (lemongrass) essential oil against Aedes aegypti . The study combines Thin Layer Chromatography (TLC) profiling of both the essential oils, and larvicidal bioassay and contact irritancy assays against Aedes aegypti to assess biological activity. Larvicidal efficacy was evaluated by exposing early fourth instars of Aedes aegypti larvae to different concentrations of crude and commercial essential oils. The bioassay demonstrated considerable concentration-dependent toxicity, with crude oil exhibiting higher toxicity (LC 50 : 10.485 µg/mL) in comparison to the commercial oil (LC 50 :43.504 µg/mL), which may be attributed to the diverse and differential array of bioactive secondary metabolites. Irritancy test showed significant behavioural effects, suggesting the potential use of the oils as repellents or irritants to interfere with mosquito-host contact. The study demonstrates the higher effectiveness of crude Cymbopogon citratus essential oil and suggests its use as a potential, natural alternative for mosquito control programs. The investigation offers insights into the action of major constituents of essential oils and their use in safe vector control strategies.