Insecticidal and repellent activity of essential oil from Amomum villosum Lour. and its main compounds against two stored-product insects

The Amomum villosum essential oil was obtained from hydrodistillation and was investigated by GC-MS. The main constituents were bornyl acetate (51.6%), camphor (19.8%), camphene (8.9%) and limonene (6.2%). Insecticidal toxicity of the essential oil was evaluated in this study. It showed that the essential oil possessed contact toxicity against Tribolium castaneum and Lasioderma serricorne (LD50=32.4 and 20.4 g/adult). Three monoterpenoids camphor, camphene and limonene showed strong fumigant toxicity against T. castaneum (LC50 < 2.3, LC50 = 6.2 and 6.2mg/L air). In addition, repellency of the essential oil was also evaluated. Data showed that the essential oil and all four compounds had repellent activity against T. castaneum and L. serricorne at high concentration (78.63 nL/cm(2)). But with the decrease of concentration, they showed a different degree of attractant properties.