Effect of Medicinal Plant Extracts on the Blood Sugar Trehalose of the Pulse Beetle Callosobruchus Chinensis (Coleoptera: Bruchide)

摘要

Aqueous, ethanol and acetone leaf extracts of the four medicinally important plants Vetiveria zizanoides, Asparagus racemosus, Hyptis sauveolens and Citrus limon was used to demonstrate their toxic effects on the blood sugar trehalose of the stored insect pest Callosobruchus chinensis. The plant leaves caused significant changes on the amount of trehalose and the effect was dose-dependent. Trehalose was found to be decreased compared to control insects. Acetone extract of Citrus limon at sub-lethal dose (1.6%) could produce significant effects compared to aqueous and ethanol extracts indicating the presence of more active components in it. The medicinal plants thus proved to have strong insecticidal activity against the insect pests.