Repellency and Electrophysiological Response Of Caraway and clove bud oils against bean bug Riptortus clavatus

This study was performed to investigate the repellent activity of thirteen plant essential oils and to confirm their electrophysiological response against the bean bug Riptortus clavatus . Among the tested oils, caraway (100%) and clove bud oil (92%) significantly repelled the bean bugs at a dose of 0.142 μL/cm 2 by using an olfactometer. GC-MS analysis revealed that the active components responsible for the effective repellency of caraway and clove bud oil were carvone (56%) and limonene (44%); eugenol (81%), isoeugenol (12%) and β-caryophyllene (7%), respectively. Of the different active constitutions, eugenol was the most significant one than the others with reference to repellent activity against the bean bugs. Analysis by GC-EAD showed, major components of two essential oils that elicited responses in R. clavatus antennae, indicating the potential role of the essential oils as repellents that determine the choice of the repellent material.