Abstract

The aim of this research was to determine chemical composition and insecticidal activity of the essential oil of Cananga odorata (Lam.) Hook. f. and Thomson leaves against maize weevils (Sitophilus zeamais Motschulsky). Essential oil of C. odorata leaves was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 23 components of the essential oil were identified. The principal compounds in the essential oil were linalool (21.08%), linalool acetate (16.14%), α-pinene (12.73%), eugenol (8.86%) and α-terpineol acetate (7.71%) followed by isobornyl acetate (3.56%), α-terpineol (3.46%), and camphor (3.23%). The essential oil of C. odorata leaves exhibited strong contact toxicity against S. zeamais with an LD₅₀ value of 33.14 µg/adult. The essential oil also possessed fumigant toxicity against S. zeamais with an LC₅₀ value of 14.77 mg/L. The results indicated that the essential oil of C. odorata leaves showed potential in terms of contact and fumigant toxicity against grain storage insect.

Key words: Cananga odorata, Sitophilus zeamais, contact toxicity, fumigant, essential oil composition.