Fumigant toxicity study of different essential oils against stored grain pest Callosobruchus chinensis

Abstract

Essential oils were extracted from five aromatic plant species namely Cinnamon essential oil (Cinnamomum zeylanicum, C. verum), Clove essential oil (Syzygium aromaticum), Rosemary essential oil (Rosmarinus officinalis), Bergamot essential oil (Citrus Bergamia) and Japanese Mint essential oil (Mentha arvensis) by steam distillation. Bioassays, i.e. fumigation with pure essential oils were carried out on adults. Observations were taken after 24 h, 48h, 72 h and 96 h respectively. The LC50 values obtained for 24 h, 48 h, 72 h and 96 h was 0.712(0.597-0.859)%, 0.345(.069-0.474)%, 0.479(0.332-0.602)% and 0.397(0.234-0.511)% respectively. The LC50 values obtained for 24 h, 48 h and 72 h for rosemary essential oil are 3.282, 4.261 and 1.509 respectively while the LC50 values obtained for clove oil for 24 h, 48 h and 72 h were 0.334, 0.341 and 0.059 respectively. The present study demonstrated fumigant toxicity against the stored grain pest Callosobruchus chinensis. The essential oil showed potential to be developed as possible natural fumigants or repellents for control of the pulse beetle.