Recent, Eco-friendly Approach for Controlling Culex pipiens (L.) using Novel Synthesized Cadmium Sulphide Nanoparticles of Ocimum basillicum Extract

Mosquitoes are the key vector for the transmission of serious parasites and pathogens which affect many people worldwide. The massive overuse of synthetic mosquito insecticides had developed resistance in mosquitoes. Therefore, the need for reliable and eco-friendly control techniques became crucial. Nanoparticle fabrication is a cutting-edge and trending method. The green production of cadmium sulphide nanoparticles (CdS NPs) utilizing Ocimum basillicum leaves as a sophisticated and effective strategy against Culex pipiens was demonstrated in this study. CdS nanoparticles are characterized by a series of techniques including UV-Vis spectrophotometry, High-Resolution Transmission Electron Microscope (HRTEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). CdS nanoparticles (CdS NPs) were highly effective against the larvae (3^rd instars) of Culex pipiens after 24 hours of treatment. The LC₅₀ of CdS NPs was 0.0113 g/l. Meanwhile, the LC₅₀ of Ocimum basillicum aqueous extract of leaves was 52.36 g/l. There was no mortality in the control group. CdS NPs also increased larval and pupal duration significantly. Furthermore, it had a deleterious impact on pupation and adult emergence rates. Post-treatment imaging using a light microscope and scanning electron microscopy (SEM) results in larvae had deformities and constrictions in the head and thorax area. The abdomen (digestive tract and respiratory canal) was completely deformed, however, the syphon remained unaffected with typical spiracular valves and very minor abnormalities on the tracheal trunk surface and muscle fibre. Conclusion: Overall, this study suggested that the use of Ocimum basillicum leaves extract mediated synthesis of CdS nanoparticles can be used for controlling Culex pipiens. This is the first study to look at the larvicidal potential of CdS NPs synthesized by Ocimum basillicum leaves extract against Culex pipiens and the potential impacts.