Vol. 12, Issue 5 (2023)

Author(s):
Jagadish, GS Mamatha, Ravikumar C, Jaya Nagappa Lakkundi, ShriKrishna Isloor, Shilpa VT, Prasad TNKV, Ananda KJ and Yathish HM

Abstract:
An insecticidal efficacy of silver nanoparticles (AgNPs) synthesized from aqueous dried leaf extract of E. tereticornis and P. pinnata were evaluated against adult flies, larvae and pupae of S. calcitrans by in vitro assays at different concentrations. The flies collected from in and around cattle dairy farm at Livestock Farm Complex, Veterinary College, Hebbal, Bengaluru were identified based on their morphology and further reared in the laboratory in customized insect cages. The synthesized AgNPs were Nano characterised by UV-Visible spectroscopy, Zeta potential analysis, Dynamic light scattering, Scanning electron microscopy and Fourier transform infrared spectroscopy before in vitro assays. An adulticidal assay by filter paper impregnation method in triplicates showed the highest mortality of 70.0 percent against adult flies of S. calcitrans at 20 mg per litre after 24 hours exposure. The LC₂₅, LC₅₀ and LC₉₀ values were 1.073, 9.218 and 546.86, respectively. The larvicidal assay by diet incorporation method indicated 100.0 percent larval mortality at 20 mg concentration per litre after 48 hours exposure and the LC₂₅ (0.0873), LC₅₀ (2.294) and LC₉₀ (14.375) values were observed. The pupicidal assay showed the highest percent inhibition of adults emergence (45.0%) from pupae at 8 mg per ml concentration after 24 hours of dipping. The LC₂₅, LC₅₀ and LC₉₀ values observed were 0.412, 1.921, and 35.801, respectively. The probit analysis revealed the significant effect with different concentrations of AgNPs synthesized from aqueous dried leaf extract. However, further field trial assays should be explored for their suitable application.