Antifeedant activity of invasive Prunus serotina leaves methanolic extract against Sitophilus granarius, a pest of stored products.

Abstract

Synthetic pesticides pose a risk to the environment and human health by contaminating soil, water, and food chains. Natural plant-based alternatives offer a safer and more sustainable solution by reducing pollution, supporting biodiversity, and minimising pesticide resistance. This study evaluated the antifeedant activity of methanolic leaves extracts from invasive black cherry (Prunus serotina Erhr.) against a storage pest, the granary weevil (Sitophilus granarius L.). Chromatographic analysis of P. serotina leaves methanolic extracts identified 10 main phenolic compounds, with ursolic acid, p-coumaric acid o-coumaric acid, and caffeic acid exceeding 10%. LC-MS/MS analysis detected 12 compounds above the limit of quantification (LOQ), with luteolin-7-O-glucoside, caffeic acid, and chlorogenic acid at the highest concentrations. The antifeedant activity of P. serotina leaves methanolic extract was tested using the wheat wafer method, showing medium antifeedant effects at all extract concentrations (3.5, 5.0, and 12.0 mg/mL). Both males and females fed significantly less extract-treated wafers, with the inhibition of female feeding being stronger at 12.0 mg/ml. The extracts of P. serotina effectively discourage feeding of S. granarius, and the potency increases with concentration. Their flavonoids, phenolic acids, and cyanogenic glycosides suggest a complex mode of action, making them a promising natural alternative to synthetic insecticides. Further research should isolate key active compounds and evaluate their efficacy as botanical pesticides.