Essential oil of chinese medicinal herb,Evodia rutaecarpaunripe fruits was found to possess insecticidal activity against maize weevils,Sitophilus zeamais and red flour beetlesTribolium castaneum. The essential oil ofE. rutaecarpawas obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 38 components of the essential oil were identified. The principal compounds inE. rutaecarpaessential oil wereβ-myrcene (17.7%), (Z)-β-ocimene

more »

... e (14.7%),γ-terpinene (6.4%), linalool (5.7%) andβ-thujene (5.1%). Bioactivity-guided chromatographic separation of the essential oil on repeated silica gel columns led to isolate three volatile components (β-myrcene,β-ocimene andα-phellandrene) from the essential oil.α-Phellandrene was strongest fumigant againstS. zeamaisadults,T. castaneumadults andT. castaneumlarvae with LC50values of 15.61, 19.78 and 47.96 mg/L air, respectively.β-Myrcene andβ-ocimene also possess fumigant activity against the two species of insects but weaker fumigant activity than the crude essential oil.