Improved pesticidal activity of fungal metabolite from nomureae rileyi with chitosan nanoparticles

The present study was undertaken to evaluate LC₅₀ and LT₅₀ of Chitosan Nano-particle Coated Fungal metabolite (CNPCFM) and Uncoated Fungal Metabolite (UFM) and Fungal Spores (FS) of entomopathogenic fungi Nomuraea rileyi (F) Samson on the pest Spodoptera litura, through which the pesticidal activity was improved using chitosan nanoparticles. Fungal Metabolite (FM) was extracted using ethyl acetate from the Fungal Filtrate (FF). Fungal metabolite was coated with chitosan nanoparticle. All the three, Fungal Spores (FS), Chitosan Nano-particle Coated Fungal metabolite (CNPCFM) and Uncoated Fungal Metabolite (UFM) were tested and confirmed that they were capable of infecting S. litura. Among the three tested, CNPCFM was found to be more effective than UFM and FS (P <; 0.05). The LC₅₀ and LT₅₀ values were increased as the larvae grew older. As the instars advanced, a decrease in mortality and an increase in time for CNPCFM, UFM and FS were recorded. LC₅₀ value for I, II, III and IV instars were 1.67 μg, 1.85 μg, 1.98 μg and 2.45 μg respectively when CNPCFM sprayed. LC₅₀ value for I, II, III and IV instars were1.87 μg, 2.01 μg, 2.38 μg and 3.97 μg respectively when UFM sprayed. For FS, LC₅₀ values were 2.28 × 108 Spores/ml, 2.92 × 106 Spores/ml, 4.75 × 010 Spores/ml and 5.55 × 1010 Spores/ml for I, II, III and IV instars respectively. UFM showed better LC₅₀ value when compared to the FS and less effective than the CNPCFM. When the instars grew older, a decrease in mortality and an increase in LT₅₀ were recorded with respect to the concentration of CNPCFM, UFM and FS. Adult longevity (LT₅₀) value for CNPCFM, UFM and FS were 2.17± 0.2 hrs 4.21± 0.2hrs and 32.7 ± 0.2hrs respectively. Hence the present study confirms that Chitosan Nano-particle - oated Fungal metabolite (CNPCFM) showed higher pesticidal activity when compared with Uncoated Fungal Metabolite (UFM) and Fungal Spores (FS).