- International Journal of Pure and Applied Zoology (2014) Volume 2, Issue 3
Toddalia Asiatica (L.) Lam. Essential Oil: A Potential Natural Fumigant and Repellent Against Three Coleopteran Pests of Stored Products
The essential oil of Toddalia asiatica was isolated from the leaves and tested for its fumigant toxicity and repellency against Callosobruchus maculatus, Sitophilus oryzae and Tribolium castaneum. In the toxicity studies, the LC50 concentration was the lowest (53.88μl) against C. maculatus, which showed that it was the most susceptible pest. The LC50 concentrations against S. oryzae and T. castaneum were 77.77 and 99.12 μl, respectively in 24h. LC90 concentrations of the essential oil of T. asiatica against C. maculatus, S. oryzae and T. castaneum were recorded as 95.47, 138.77 and 175.69 μl, respectively. After 1 h exposure, the repellent activity was 71% against C. maculatus and S. oryzae and 67% against T. castaneum at 20μl concentration compared to control. The repellent activity increased with the increase in the concentration. When the exposure period was increased to 3h the repellency was increased to 100% against C. maculatus and S. oryzae and 89.57% against T. castaneum. The major components identified in the essential oil of T. asiatica were β- Linalool (10.67%), β - Sesquiphellandrene (9.86 and 2.2%), Spathuleno (8.37%), Caryophyllene oxide (6.29%), pogostol (5.2%) and Methyl methylanthranilate (5.45%) and linalyl acetate (4.24%). The results clearly suggested that the essential oil of T. asiatica can be used to control C. maculatus, S. oryzae and T. castaneum in warehouses.
Author(s): Gopal Nattudurai, Michael Gabriel Paulraj and Savarimuthu Ignacimuthu