Abstract

Essential oil of Dracocephalum moldavica flowering aerial parts was extracted via hydrodistillation. A total of 38 components of the essential oil were identified. 1, 8-Cineol (31.25%) and 4-terpineol (22.82%) were the two main components of the essential oil followed by cumin alcohol (4.29%) and α-terpineol (4.21%). The essential oil exhibited strong fumigant toxicity against Sitophilus zeamais and Tribolium castaneum adults with LC₅₀values of 2.65 and 0.88 mg/L, respectively. The essential oil also showed contact toxicity against S. zeamais and T. castaneum adults with LD₅₀ values of 22.10 and 18.28 mg/adult, respectively. The essential oil of D. moldavica may have the potential to be developed as a new natural fumigant/insecticide for the control stored product insects.

Key words: Dracocephalum moldavica, Sitophilus zeamais, Tribolium castaneum, contact toxicity, essential oil composition.