Effect of essential oils as repellent against coleopteran pests of stored produce

An attempt was made to test the repellent action of oils of Lantana camara (Lantana), Citronella nardus (Citronella), Cinnamomum zeylanicum (Cinnamon) and Trachyspermmum copicum (Ajwain) against four major coleopteran stored product pests viz., pulse beetle, Callosobruchus chinensis L., rice weevil, Sitophilus oryzae L., lesser grain borer Rhyzopertha dominica F. and red flour beetle Tribolium castaneum H. The oils of Lantana and Citronella were extracted from leaves, Cinnamon from barks and Ajwain from seeds. The results of the repellency test revealed that, essential oil of C. nardus found to have high repellency when compared to other three oils against C. chinensis and T. castaneum, whereas S. oryzae and R. dominica were repelled greatly by L. camara essential oil at both 2 and 4 h after treatment. The repellency effect increases with increase in concentration and also increase in Hours After Treatment (HAT).