AbstractBACKGROUND: In a screening programme for new agrochemicals from Chinese medicinal herbs, the essential oil of Atractylodes chinensis (DC.) Koidz was found to possess strong insecticidal activity against the common vinegar fly, Drosophila melanogaster L. The essential oil was extracted via hydrodistillation, and its constituents were determined by GC‐MS analysis.RESULTS: The main components of A. chinensis essential oil were β‐eudesmol (21.05%), β‐selinene (11.75%), γ‐elemene (7.16%) and isopetasam (5.36%). Bioactivity‐directed chromatographic separation on repeated silica gel columns led to the isolation of five compounds, namely atractylon, α‐elemol, β‐eudesmol, hinesol and β‐selinene. β‐Selinene, α‐elemol and hinesol showed pronounced contact toxicity against D. melanogaster adults, with LD50 values of 0.55, 0.65 and 0.71 µg adult−1 respectively. Atractylon and β‐eudesmol were also toxic to the fruit flies (LD50 = 1.63 and 2.65 µg adult−1 respectively), while the crude oil had an LD50 value of 2.44 µg adult−1.CONCLUSION: The findings suggested that the essential oil of Atractylodes chinensis and its active constituents may be explored as natural potential insecticides. Copyright © 2011 Society of Chemical Industry