Evaluation of the Larvicidal and Repellency of Extracts and Silver Nanoparticles Biosynthesized with Zataria multiflora (Shirazi Thyme) against Anopheles stephensi.

Introduction: Mosquitoes transmit several diseases to humans. New and environmentally safe methods are needed to control mosquito populations effectively. This study aimed to evaluate the larvicidal and repellent properties of extracts and silver nanoparticles synthesized from Zataria multiflora (Shirazi thyme). Methods: To determine the larvicidal and repellent properties of Z. multiflora, we tested different concentrations of synthesized silver nanoparticles and crude extract against this malaria vector. Results: The crude extract exhibited weak larvicidal activity, with an LC50 of 616.52 μg/mL and an LC90 of 1109.74 μg/mL. However, the synthesized silver nanoparticles are highly active on the larvae of Anopheles stephensi, with an LC50 at 51.07 μg/mL and an LC90 at 119.04 μg/mL. Both the crude extract (ED50: 0.00031 μg/cm2; ED90: 0.0018 μg/cm2) and silver nanoparticles (ED50: 0.000072 μg/cm2; ED90: 0.00048 μg/cm2) demonstrated significant repellent activity. Particle size analysis revealed a range of 24.56 to 63.76 nanometers, with an average size of 52.7 nanometers. Conclusion: This study showed that Z. multiflora silver nanoparticles have significant larvicidal properties, so they are suggested as a nature-friendly larvicide.