Pesticidal and pest repellency activities of roots of Laportea crenulata (Gaud.) against Tribolium castaneum (Herbst)

Abstract

The presence of Tribolium castaneum (Herbst) in a stored food results in contamination and substantial economic damage due to loss of the products and a decrease in nutritional value. This study was conducted to determine the pesticidal and pest repellent activities of roots of Laportea crenulata Gaud. against T. castaneum. Pesticidal activity was determined using surface film method, whereas, filter paper disc method was used to determine the pest repellency property of the plant. Both chloroform and methanol soluble fractions of ethanol extracts of roots of L crenulata were found to possess pesticidal property. High mortality record (77-83% at 24-48 hours exposure duration) for chloroform fraction was found at a dose 1.77mg/cm2. On the other hand, methanol fraction showed high mortality records (80-93%) at doses 0.44-1.77 mg/cm2, suggesting its superior pesticidal potency. Although, both fractions also showed pest repellency property, chloroform fraction has higher activity than methanol fraction. These results suggests that roots of L. crenulata possess both pesticidal and pest repellency activities against T castaneum and can be used in controlling pest of grain and flour based products.