Effect of ZnO and TiO2 (Anatase) Nanoparticles And Their Combination In Controlling Mosquito Population Of Anopheles Stephensi, Aedes Aegypti And Culex Quinquefasciatus: An In Vitro Study

Both zinc oxide nanoparticles (ZnO NPs), as well as titanium dioxide nanoparticles (TiO2 NPs, anatase), are being used in many fields, and have also been previously confirmed to have potential mosquito population control properties. Therefore, this study intended to evaluate the effect of ZnO, TiO2 and combination of ZnO and TiO2 NPs on larvae of Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. At various concentrations for 24 hours (2, 4, 6, 8 & 10 ppm), ZnO, TiO2 and combination of ZnO and TiO2 NPs were treated on larvae of An. stephensi, Ae. aegypti and Cx. quinquefasciatus. Results revealed that treatment of NPs significantly increased the mortality of larvae. Anopheles stephensi larval mortality LC50 values were 3.609, 3.478 and 2.612 ppm while LC90 values were 13.08, 11.942 and 8.305 ppm, respectively for ZnO, TiO2 and combination of ZnO and TiO2 NPs. In Ae. Aegypti larva, LC50 ranges of ZnO, TiO2 and combination of ZnO and TiO2 NPs were 3.756, 3.455 and 2.594 ppm, while LC90 values were 12.204, 10.543 and 9.555 ppm, respectively at 24 hours exposure. LC50 value of ZnO, TiO2 and combination of ZnO and TiO2 NPs against Cx. quinquefasciatus larvae were 3.896, 3.763 and 2.589 ppm, while LC90 values were 13.567, 13.178 and 8.680 ppm, respectively at 24 hours exposure. Furthermore, the histopathological changes were observed in the ZnO and TiO2 NPs in combination treated midgut region of 3rd instar larvae of selected mosquitoes. The combination of ZnO and TiO2 NPs provided prominent larval mortality at low dose than other individual NPs treatments. The present investigation clearly concludes that the combination of ZnO and TiO2 NPs treatment would be a good candidate for controlling the mosquito Population