FUMIGANT AND REPELLENT EFFECTS OF SELECTED ESSENTIAL OILS AGAINST SITOPHILUS GRANARIUS (L.) (COLEOPTERA: CURCULIONIDAE)

The granary weevil (Sitophilus granarius) is a serious insect pest that causes economic losses to stored grains and their products.The effectiveness of essential oils (EOs) against the granary weevil has been studied; nevertheless, there is still a lack of data on the comparison of EOs fumigation and repellency effects.This study aimed to compare the fumigant toxicity and repellent effects of the 8 EOs, clove (Syzygium aromaticum), river red gum (Eucalyptus camaldulensis), garlic (Allium sativum), ginger (Zingiber officinale), lemon (Citrus lemon), mint (Mentha longifolia), almond (Prunus dulcis), and basil (Ocimum basilicum) against adults of the granary weevil.The fumigation bioassay showed that clove EO was the most toxic EO, with the lowest calculated LC50 value of 0.52% after 48 h of exposure.The 1, 2, 4, and 8% concentrations of S. aromaticum had a great fumigant effect against granary weevil compared with the other tested EOs.The 2, 4, and 8% concentrations of clove EO have a significant effect on the repellency percentage of granary weevil compared with river red gum, garlic, ginger, lemon, mint, almond, and basil after 20 min and 120 min of exposure test.Thus, using clove EO as a fumigant and repellent to treat cereal grains and their products infested by granary weevil may play a significant role in controlling this serious pest.