Repellent and Toxicant Effects of Eight Essential Oils against the Red Flour Beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae).

This study was conducted to compare the repellent effect and contact toxicity of eight essential oils (EOs), including Syzygium aromaticum , Allium sativum, Eucalyptus camaldulensis , Lavandula officinalis , Simmondsia chinensis , Matricaria chamomilla , Citrus limon , and Prunus dulcis , against adults of Tribolium castaneum Herbst. Four concentrations (1, 5, 10, and 15% in acetone solvent) of each EO were tested. The 5, 10, and 15% concentrations of S. aromaticum EO had a high repellency effect against T. castaneum compared with A. sativum , E. camaldulensis , L. officinalis , S. chinensis , M. chamomilla , C. limon , and P. dulcis after 30 min of exposure. The repellency test of the S. aromaticum , E. camaldulensis , L. officinalis , M. chamomilla , C. limon , and P. dulcis EOs on T. castaneum has shown that the mortality percentages enhanced with the increase in the EOs concentration and also with the exposure time. The 15% concentration of P. dulcis and M. chamomilla EOs have a significant impact on the mortality rate of T. castaneum compared with S. aromaticum , A. sativum, E. camaldulensis , L. officinalis , and S. chinensis after the 24 h of contact test. Moreover, the 15% concentration of the C. limon EO caused a greater mortality percentage compared with S. aromaticum , A. sativum, E. camaldulensis , and L. officinalis . It could be concluded that using the S. aromaticum EO as a repellent oil and using P. dulcis, M. chamomilla , and C. limon for contact toxicity to treat the flour infested by T. castaneum can play an important role in protecting stored grains and their products.