Fumigant toxicity of essential oils from the Myrtaceae family and 1,8-cineole against 3 major stored-grain insects

Six out of 42 essential oils extracted from species of the family Myrtaceae found in Australia were shown to have potent fumigant toxicity against three major stored-grain insects: Sitophilus oryzae, Tribolium castaneum and Rhyzopertha dominica. These were the essential oils from Eucalyptus nicholii, E. codonocarpa, E. blakelyi, Callistemon sieberi, Melaleuca fulgens and M. armillaris. The LD50 and LD95 of the selected essential oils against S. oryzae adults were between 19.0-30.6 and 43.6-56.0 mul/l air, respectively. Also, these oils were approximately twice as toxic to T castaneum and R. dominica at the LD95. Fumigant effects of the essential oils rich in 1,8-cineole were considered to warrant further research into their potential for commercial use. (C) 2004 Elsevier Ltd. All rights reserved.