Insecticidal activity and chemical composition of the essential oils of Artemisia lavandulaefolia and Artemisia sieversiana from China.

In our screening program for new agrochemicals from local wild plants, Artemisia lavandulaefolia and A. sieversiana were found to possess insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of the aerial parts of the two plants were obtained by hydrodistillation and analyzed by GC and GC/MS. The main components of A. lavandulaefolia oil were caryophyllene (15.5%), beta-thujone (13.8%), eucalyptol (13.1%), and beta-farnesene (12.3%), and the principal compounds identified in A. sieversiana oil were eucalyptol (9.2%), geranyl butyrate (9.2%), borneol (7.9%), and camphor (7.9%). The essential oils of A. lavandulaefolia and A. sieversiana possessed fumigant toxicity against S. zeamais adults with LC(50) values of 11.2 and 15.0 mg/l air, respectively. Both essential oils also showed contact toxicity against S. zeamais adults with LD(50) values of 55.2 and 112.7 microg/adult, respectively.