A study on the larvicidal and adulticidal potential of Cladostepus spongiosus macroalgae and green-fabricated silver nanoparticles against mosquito vectors

Abstract

Mosquito vectors in the present universe cause a major problem due to the transmission of pathogens with high morbidity. The present research aimed to explore the larvicidal and adulticidal toxicity of the Cladostepus spongiosus extract and its fabricated AgNPs on key mosquito vectors. The synthesized AgNPs were confirmed by UV-Vis spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrophotometry, and X-ray diffraction analysis. In the mosquitocidal assay, the C. spongiosus extract has shown good larvicidal mortality against Aedes aegypti (88.9%), Anopheles stephensi (84.1%), and Culex. quinquefasciatus (81.6%). Further, adulticidal mortality percentages were 78.8%, 75.4%, and 67.6% against An. stephensi, Ae. Aegypti, and Cx. quinquefasciatus at 1,000 ppm. AgNPs revealed larvicidal mortality percentages of 94.8% against An. stephensi, 92.8% against Ae. Aegypti, and 90.6% against Cx. quinquefasciatus; the adulticidal potential was also revealed to be higher against An. stephensi (89.4%) followed by Ae. aegypti (86.8%) and Cx. quinquefasciatus (83.2%). Comparing the results achieved from the C. spongiosus extract and its derived AgNPs, promising activity was attained against key mosquito vectors at a minimal dose of 70 ppm of AgNPs. Thus, C. spongiosus-mediated AgNPs can be an alternative tool in controlling key mosquito vectors.

Keywords

• nano-biotechnology
• macroalgae
• bio-toxicity
• mosquito-borne diseases
• dengue