Repellency and Phytoxicity Assessment of Plant Extracts, Essential Oils and Nanoparticles on Tribolium castaneum Herbst Beetles Infesting Wheat Grains (Triticum estivum L.)

Abstract

Plant extracts and nanoparticles were tested for Tribolium castaneum Herbst Beetle repellency and wheat grain phytotoxicity. Mugwort plant extract had 100% repellency after 3 hours for 10%, 15%, and 20% concentrations, 85% after 2 hours at 20%, and 82% at 15%. The lowest significant repellency values for Mugwort (Artemisia annua) plant extract and EOs after 1 hour were 42% and 54% at 5% concentration. After 3 hours, plant extract and essential oil at 10%, 15%, and 20% concentrations repelled black seeds (Nigella sativa) 100%. Black seeds plant extract had 93% repellency at 20% after 2 hours and 85% at 5% after 3 hours, compared to 50% for EOs. The lowest significant repellency values for plant extract and EOs after 1 hour were 50% and 52% at 5% concentration. SiNPs and AgNPs have similar repellency values across exposure times. SiNPs and AgNPs had 40% repellency at 100 ppm after 1 hour compared to the control. After 1 hour of exposure, SiNPs had 2% repellency and AgNPs 4% at 100 ppm. Phytotoxicity tests showed that wheat grains did not affect seed germination characteristics or biological measurements. In treated wheat grains, most germination and biological indices increased. This shows that these treatments did not kill the wheat embryo. These findings suggest that these treatments could protect grains, particularly wheat, for human consumption, animal feed, or agricultural cultivation.