Abstract

The essential oil was extracted by Soxhlet method with anhydrous diethyl ether fromAilanthus altissima Swingle (Sapindales: Simaroubaceae) bark, a traditional Chinese herbal plant and its repellent, contact and fumigant activities were investigated against four major stored grain insects. A. altissima bark oil significantly repelledTribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Oryzaephilus surinamensis (Linnaeus) (Coleoptera: Silvanidae), Sitophilus oryzae (Linnaeus) (Coleoptera: Curculionidae) and Liposcelis paeta Pearman (Psocoptera: Liposcelididae) adults, with the repellency value reaching IV grade or stronger during the whole exposure period. A. altissima bark oil also pos-sessed strong contact toxicity on S. oryzae adults which gradually enhanced with increased exposure time and the corrected percentage mortality reached 76.5% after 72 h treatment. Furthermore, A. altissima bark oil had high fumigant activity against O. surinamensisand S. oryzae adults with the corrected percentage mortality 99.3 and 81.9% within 24 h, respectively.

Key words: Ailanthus altissima bark, essential oil, stored-grain insects, bioactivity.