Chemical composition and insecticidal activity against Sitophilus zeamais of the essential oils of Artemisia capillaris and Artemisia mongolica.

In our screening program for new agrochemicals from local wild plants, Artemisia capillaris and A. mongolica were found to possess insecticidal activity against the maize weevil, Sitophilus zeamais. The essential oils of aerial parts of the two plants were obtained by hydrodistillation and were investigated by GC and GC-MS. The main components of A. capillaris essential oil were 1,8-cineole (13.75%), germacrene D (10.41%), and camphor (8.57%). The main constituents of A. mongolica essential oil were alpha-pinene (12.68%), germacrene D (8.36%), and gamma-terpinene (8.17%). Essential oils of A. capillaris and A. mongolica possess fumigant toxicity against S. zeamais adults with LC50 values of 5.31 and 7.35 mg/L respectively. The essential oils also show contact toxicity against S. zeamais adults with LD50 values of 105.95 and 87.92 microg/adult, respectively.