Antifeedant Activity Of Lantana Camara Nano Suspension Prepared By Reverse Emulsion Of Ethyl Acetate Active Fraction At Various Surfactant Organic-Phase Ratio

Lantana camara ethyl acetate fraction (EAF) is a promising alternative to control Crocidolomia pavonana and interestingly provide antifeedant activity against C. pavonana. This study aims to prepare the EAF suspension in water solvent by reverse emulsion method with low energy-phase inversion nano-emulsification with vary in the surfactant organic-phase ratio (SOR) 9, 11, 12, and 14. The observed Fourier transform infra-red spectra showed that tween 80 successfully covered the EAF suspension in all SOR variation. The particle size analyzer and zeta potential measurement showed that the L. camara EAF with SOR 11 received a higher fraction of nanoparticles (77%) with an average size of 8.3 +/- 1.3 nm and highest zeta potential (-8.9 mV) compared to other SOR. Also, SOR 11 contributed to the lowest contact angles measurement (48.50 degrees) lead to the best wettability caused EAF suspension properly deposited on the cabbage leaf surface. It was highlighted that the EAF SOR 11 enhanced larvae efficacy with the highest mortality (86.67%) (P < 0.05) and LC50 0.39% at 48 h determined as the medium toxicity category against 3rd instar larvae C. pavonana. The suspension of L. camara fraction with SOR 9 and 11 considered as a strong antifeedant activity significantly against 3rd instar larvae C. pavonana. It was emphasized SOR 11 displayed a higher antifeedant coefficient consequently received stronger antifeedant activity compared to SOR 9. It was concluded that a higher fraction of nanosize particles, stability, and lower wettability of EAF SOR 11 suspension compared to other formulas considered responsible for the excellent antifeedant performance.