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 alternative
available in preventing and controlling such diseases. Thus, there is an urgent need to check
the proliferation of the population of vector mosquitoes in order to reduce vector-borne diseases by
appropriate control methods. This study investigated the effect of the entomopathogenic fungus, Metarhizium
anisopliae against Cx. quinquefasciatus larvae, as well as its effect when combined with
zinc oxide (ZnO) and aluminum oxide (Al2O3) nanoparticles (NPs). Larvae were exposed to different
concentrations of fungus, M. anisopliae (1.42×105, 1.42×106, 1.42×107, 1.42×108 spore/ml). Mortality
rates of fourth instars ranged from 100% for the highest spore concentration to 80% for lowest spore
concentration tested. Larvae exposed to different concentrations of ZnO & Al2O3 (5, 10, & 30mg/ l)
combined individually with low concentration of fungus, M. anisopliae, showed significantly high
rates 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 larval
cuticle in different body parts. The combination of NPs and fungus had a synergistic effect on larvae
mortality. This study showed that addition of the synthesized nano-metal oxides to M. anisopliae have
greater efficacy on control of Cx. quinquefasciatus larvae.