Composition and Toxicity of Essential Oil of Illicium simonsii Maxim (Illiciaceae) Fruit against the Maize Weevils

The essential oil of Illicium simonsii fruit was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 40 components of the essential oil were identified. The principal compounds in I. simonsii fruit essential oil were �-caryophyllene (10.30%), �-cadinene (9.52%), methyl eugenol (8.94), �-elemene (5.84%), and �-amorphene (5.20%). The essential oil possessed strong fumigant toxicity against Sitophilus zeamais adults with a LC 50 value of 14.95 mg/L air. The essential oil also showed contact toxicity against S. zeamais adults with a LD 50 value of 112.74 µg/adult.