Abstract Mosquito-borne diseases continue to pose significant public health challenges worldwide, necessitating the development of environmentally sustainable alternatives to synthetic insecticides. The present study evaluated the larvicidal efficacy of aqueous leaf extracts of Mentha arvensis , Azadirachta indica , Eucalyptus globulus , Cymbopogon citratus , and Ocimum sanctum against different larval instars of Culex quinquefasciatus under laboratory conditions. Larval bioassays were conducted using three concentrations (0.3, 0.6, and 0.9%) and mortality was recorded after 24 and 48 h of exposure. All botanical extracts exhibited larvicidal activity, with mortality generally increasing with concentration and exposure duration. Among the tested botanicals, M. arvensis showed the highest efficacy, causing 96.66% mortality in third instar larvae at 0.9% concentration after 48 h exposure, followed by A. indica (93.33%), E. globulus (90.00%), C. citratus (86.66%), and O. sanctum (80.00%). Larval susceptibility varied among developmental stages, with third instar larvae generally exhibiting greater mortality than other instars, whereas fourth instar larvae were comparatively less susceptible. The findings demonstrate the potential of aqueous botanical extracts, particularly M. arvensis and A. indica , as eco-friendly larvicidal agents against C. quinquefasciatus . Further investigations on active constituents, formulation development, and field validation are required to facilitate their incorporation into sustainable mosquito management programmes.
Singh et al. (Wed,) studied this question.