CONTROL OF HUMAN FILARIAL VECTOR, CULEX QUINQUEFASCIATUS (DIPTERA: CULICIDAE) THROUGH COMBINATION OF THE ENTOMOPATHOGENIC FUNGUS, METARHIZIUM ANISOPLIAE AND NANOPARTICLES OF ZINC OXIDE AND ALUMINUM OXIDE

Abstract

Culex quinquefasciatus (Diptera: Culicidae) is a vector of many pathogens and parasites of humans,as well as domestic and wild animals. Its eradication or control is regarded as one of the important alternativeavailable in preventing and controlling such diseases. Thus, there is an urgent need to checkthe proliferation of the population of vector mosquitoes in order to reduce vector-borne diseases byappropriate control methods. This study investigated the effect of the entomopathogenic fungus, Metarhiziumanisopliae against Cx. quinquefasciatus larvae, as well as its effect when combined withzinc oxide (ZnO) and aluminum oxide (Al2O3) nanoparticles (NPs). Larvae were exposed to differentconcentrations of fungus, M. anisopliae (1.42×105, 1.42×106, 1.42×107, 1.42×108 spore/ml). Mortalityrates of fourth instars ranged from 100% for the highest spore concentration to 80% for lowest sporeconcentration tested. Larvae exposed to different concentrations of ZnO & Al2O3 (5, 10, & 30mg/ l)combined individually with low concentration of fungus, M. anisopliae, showed significantly highrates of mortality reaching 100% and 96.25% for ZnO & Al2O3, respectively after 4 days of treatment.SEM micrographs confirmed the attachment and penetration of the fungus M. anisopliae into the larvalcuticle in different body parts. The combination of NPs and fungus had a synergistic effect on larvaemortality. This study showed that addition of the synthesized nano-metal oxides to M. anisopliae havegreater efficacy on control of Cx. quinquefasciatus larvae.