Chemical composition and fumigant toxicity of essential oils from ten aromatic plants growing in Egypt against different stages of confused flour beetle, Tribolium confusum Jacquelin du Val

Essential oils may provide green and safe alternatives to currently used fumigants and insecticides for the management of stored-product insects. This study reports the chemical analysis and fumigant toxicity of 10 essential oils against Tribolium confusum. The essential oils were obtained by hydrodistillation. The chemical profile of essential oils was determined by gas chromatography-mass spectrometry. The essential oils consisted mainly of monoterpene hydrocarbons and oxygenated monoterpenes except the oil of Artemisia monosperema which was enriched with benzenes. The essential oil of Schinus molle (LC50 = 2.22 mu l/L air) revealed the highest toxicity against T. confusum eggs, followed by Calistemon viminalis (LC50 = 5.38 mu l/L air) and Eucalyptus camaldulensis (LC50 = 5.80 mu l/L air) after 7 days of exposure. The toxicity of essential oils against larvae improved significantly with increasing exposure time. The oils Origanum vulgare and Cupressus macrocarpa caused the highest larval mortality with LC50 values of 22.81 and 25.11 mu l/L, respectively, after 7 days of exposure. Furthermore, O. vulgare essential oil was the most potent toxicant against adults after three exposure times displaying LC50 values of 5.59, 1.57 and 1.26 mu l/L air after 1, 3 and 7 days, respectively. Furthermore, the essential oils of Citrus paradisi, A. monosperema, E. camaldulensis and S. molle displayed promising fumigant toxicity against adults. Based on the obtained results, the essential oils of O. vulgare, S. molle, C. viminals, C. paradisi and A. monosperema had potent fumigant toxicity against T. confusum different stages and they could be applicable for the management of this insect.