Larvicidal and adulticidal activities of Cymbopogon citratus synthesized silver nanoparticles in different mosquito vectors

Abstract

Mosquito-borne diseases are checked by controlling the mosquito population with innovative scientific interventions. The present study aims to synthesize silver nanoparticles using aqueous leaf extract of Cymbopogon citratus (CY-AgNPs) and testing their larvicidal and adulticidal potential against medically important genera of mosquitoes-Anopheles spp., Aedes spp., and Culex spp. The synthesized nanoparticles were characterized by UV/Visible spectroscopy, FESEM, EDX, XRD, and FTIR. Larvicidal and adulticidal assays were performed against different mosquito genera as per WHO (2005 and 2022) standard protocols with slight modifications. The mortality data was subjected to One-way ANOVA and probit plane regression analysis to calculate LC₅₀, LC₉₀, and LC₉₅ values. The results with p<0.05 were considered statistically significant. The green synthesized CY-AgNPs demonstrated substantial larvicidal activity against Anopheles stephensi (LC₅₀ = 46.55 ppm), Aedes aegypti (LC₅₀ = 40.94 ppm), and Culex quinquefasciatus (LC₅₀ = 41.45 ppm). Similarly, in the adulticidal assay, the silver nanoparticles showed potency against all genera- An. stephensi (LC₅₀ = 22.48 ppm), Ae. aegypti (LC₅₀ = 20.94 ppm), Cx. quinquefasciatus (LC₅₀ = 25.34 ppm). As per the results, C. citratus-mediated silver nanoparticles showed the highest mosquitocidal activity against Aedes mosquitoes.