| Granular formulation of essential oil of wormwood, Artemisia absinthium against four stored-product pests |
| Paper ID : 1071-3IICE (R1) |
| Authors: |
|
Maryam Atapour * Assistant Professor of Entomology
Institute of Agriculture
Iranian Research Organization for Science and Technology (IROST)
PO Box 33535111
Tehran, Iran |
| Abstract: |
| Essential oils and plant extracts are the most suitable candidates as alternatives for the chemical pesticide in pest control having the lowest risk for humans and the environment. The wormwood, Artemisia absinthium L. is an herbaceous, perennial medicinal plant with straight stems growing to 80–120 centimeters. In this study, the essential oil was extracted by water distillation with clevenger method, then sodium alginates solution was used to encapsulate essential oil as granules with 0.5-4 mm diameter. For this purpose, different concentrations of essential oil were added to 1% sodium alginate solution. After 3 minutes centrifuge in 1000 rpm, this emulsion was added dropwise to a 2% CaCl2 solution. The formed granules were placed on a filter paper for 6 hours to dry and were used in the experiments. The fumigant toxicity and stability of pure and encapsulated essential oil were compared on four important stored-product pests, viz. adults of Oryzaephilus surinamensis, Tribolium confusum and Callosobruchus maculatus, and the last- instar larvae of Trogoderma granarium. Fumigant LC50 values of pure essential oil of A.absinthium were found to be 2.19, 19.01, 90.1, and 618.3 µL/L air on the four mentioned pest stages, respectively. Moreover, LC50 values increased to 8.46, 57.42, 316.42 and 2392.3 µL/L air in granules tests on the mentioned pests, respectively, proving that it required about 3-4 fold higher concentrations of essential oils in granules to produce equal mortality rate at a specified time (24 h). However, it was found that persistence toxicity duration of granules was higher compared with that of pure essential oil. On the other hand, the survival rate of the pests treated with pure extract of the essential oil decreased to zero percent after three weeks, in contrast, survival of pests treated with granule formulation was more than 80% after 8 weeks. Despite of higher durability of granular essential oil formulation compared with that of pure extract, it required higher concentrations of essential oil compared with pure extract to achieve equal effectiveness on some studied pests e.g. T.granarium in the current research. Therefore, more investigations are required to rectify the problem and obtain a standard granule formulation of the plant extract to be economically recommendable in control programs of stored-product pests. |
| Keywords: |
| Essential oil, Artemisia absinthium, Granule formulation, LC50, Persistency |
| Status : Paper Accepted (Poster Presentation) |
