The essential oil of the aerial parts of Amethystea caerulea L. was obtained from steam distillation and investigated by GC and GC-MS. The main components of the essential oil were morrilol (25.1%), 4-vinylguaiacol (14.3%) and acetoanisole (14.3%), followed by linalool (6.6%), eugenol (5.8%) and α-caryophyllene (5.2%). The essential oil showed pronounced contact toxicity against Drosophila melanogaster L. and maize weevil, Sitophilus zeamais (Motsch.), with LD(50) values of 5.18 and 50.45 µg per adult, respectively. The essential oil also possessed strong fumigant toxicity against the maize weevils with an LC(50) value of 25.39 µg mL(-1).