Chemical Composition and Insecticidal Activity of Artemisia scoparia Essential Oil against Three Coleopteran Stored-Product Insects

Chemical composition of the essential oil from Artemisia scoparia Waldst et Kit, and its fumigant and repellent activity were investigated against three stored product insects, Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.), and Tribolium castaneum (Herbst). Dry ground leaves were subjected to hydrodistillation using a modified clevenger-type apparatus and the chemical composition of the volatile oil was studied by GC-MS. Nineteen components (99.51% of the total composition) were identified. β-Pinene (19.01%), capillin (17.45%), limonene (15.11%), myrcene (10.95) were found to be the major constituents of the oil. The mortality of 1-7 day old adults of the insect pests increased with concentration from 37 to 926 μL per L air and with exposure time from 3 to 24 h. A concentration of 37 μL per L air and exposure time of 24 h was sufficient to obtain 100% kill of the insects. Callosobruchus maculatus was more susceptible than S. oryzae and T. castaneum. A second more detailed bioassay gave estimates for the LC₅₀ of C. maculatus as 1.46 μL per L air, S. oryzae 1.87 μL per L air and T. castaneum 2.05 μL per L air. Also, the essential oil was significantly more repellent to T. castaneum and S. oryzae than C. maculatus. However, half-life time of the oil for C. maculatus was longer than S. oryzae and T. castaneum. These results show the efficacy of A. scoparia oil for use in organic food protection.