Chemical Composition and Bioactivities of Alpinia Katsumadai Hayata Seed Essential Oil against Three Stored Product Insects

The aim of this research was to determine the chemical constituents and toxicity of the oil derived from Alpinia katsumadai seeds against Tribolium castaneum, Liposcelis bostrychophila and Lasioderma serricorne. The essential oil was obtained by hydrodistillation and was investigated by gas chromatograhy/mass spectrometry (GC/MS). The principal components of the essential oil were methyl cinnamate (64.2 %), cis-4-decen-1-ol (7.3 %) and octahydro-cis-2H-Inden-2-one (6.7 %). The essential oil and the two individial compounds exhibited potential insecticidal activities against three stored product insects. The essential oil possessed contact toxicity against T. castaneum, L. serricorne and L. bostrychophila (LD₅₀ = 52.6 μg/adult, 17.4 μg/adult and 35.6 μg/cm², respectively). Methyl cinnamate was the main contributor to its contact activity against T. castaneum, L. serricorne and L. bostrychophila (LD₅₀ = 5.0 μg/adult, 2.2 μg/adult and 23.5 μg/cm, respectively). The contact toxicity and repellent activity of the essential oil and cis-4-decen-1-ol against T. castaneum, L. bostrychophila and L. serricorne were recorded for the first time in this paper. A. katsumadai oil exhibited strong repellent activity against T. castaneum and L. bostrychophila, even at low concentrations. The results provide a basis of the development and utilization as biopesticide for control of insects.