Chemical Constituents and Insecticidal Activities of the Essential Oil of Cinnamomum camphora Leaves against Lasioderma serricorne.

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Cinnamomum camphora leaves was found to possess strong fumigant and contact toxicity against Lasioderma serricorne adults with LC₅₀/LD₅₀ values of 2.5 mg/L air and 21.25 µg/adult, respectively. The essential oil obtained by hydrodistillation was investigated by GC and GC-MS. The main components of the essential oil were identified to be D-camphor (40.54%), linalool (22.92%), cineole (11.26%), and 3,7,11-trimethyl-3-hydroxy-6,10-dodecadien-1-yl acetate (4.50%). Bioactivity-directed chromatographic separation on repeated silica gel columns led to the isolation of D-camphor and linalool. D-camphor and linalool showed strong fumigant toxicity (LC₅₀ = 2.36 and 18.04 mg/L air, resp.) and contact toxicity (LD₅₀ = 13.44 and 12.74 µg/adult, resp.) against L. serricorne. The results indicate that the essential oil of C. camphora and its active compounds had the potential to be developed as natural fumigants and insecticides for control of L. serricorne. [ABSTRACT FROM AUTHOR]