Effect of Some Nanometal Oxides, Entomopathogenic Fungi and their Insecticidal Activity Against <i>Spodoptera frugiperda</i> Larvae

The current study aims to study the effect of various nano metal oxides (CuO, K2O, AgO and ZnO NMOs) on maize seeds germination rates, root elongation, on germination rate of entomopathogenic fungi and insecticidal activity of these nanometal oxides (NMOs) with Bioranza 10% WP and Biovar 10% WP (entomopathogenic fungi) against Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) larvae in their 2nd instar under laboratory conditions. Five concentrations (100, 500, 1000, 5000 and 10000 ppm) of these nanometal oxides (NMOs) were tested against S. frugiperda larvae using food dip method. Maize seeds were used to test the phytotoxicity of four tested nanometal oxides (NMOs). The findings demonstrated that none of the four metal oxide NMOs had any effect on seed germination. However, CuO NMOs (93.75%) and ZnO NMOs (37.5%) significantly reduced the root elongation at 2000 mg/ ℓ after five days. In higher concentrations, the germination rates of entomopathogenic fungi (Bioranza 10% WP and Biovar 10% WP) were affected by the nano metal oxides. The fungal germination rate was impacted by the ZnO NMOs treatment at 5,000 ppm for 2hr of incubation. The germination rate for Bioranza 10% WP and Biovar 10% WP was 100%. The results showed 95% germination rates in K2O NMOs with Metarhizium anisopliae and 75% in Beauveria bassiana after 2hr of treatment at 5,000ppm. According to the insecticidal activity results, the K2O NMOs exhibited strong activity with a range of 7-95% mortality in the dip food method after 3 days of treatment. ZnO NMOs mixed with Biovar 10% WP is extremely toxic to larvae in their 2nd instar with a range of 40.6–83.4% mortality after 3 days of treatment, the K2O NMOs exhibited strong insecticidal activity with a range of 37.8–75.7% mortality.