INSECTICIDAL EFFICACY OF ESSENTIAL OILS FROM ARTEMISIA MARITIMA L. AND ZANTHOXYLUM ARMATUM DC. AND THEIR TWO MAJOR CONSTITUENTS AGAINST PLODIA INTERPUNCTELLA (HUBNER)

Essential oils isolated from Artemisia maritima L. and Zanthoxylum armatum DC were analyzed by mass spectroscopy (MS) and their main constituents were identified. Fumigant activity, repellent activity, progeny deterrency and antifeedant activity of essential oils and two constituents viz., alpha pinene and linalool were examined against the major stored product insect pest, Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae). 100% mortality was achieved by alpha pinene, linalool, A. maritima and Z. armatum oils at all concentrations within 120 hrs against P. interpunctella. Alpha pinene showed the highest repellent activity of 80.18±1.9, 88.36±1.4, 93.15±4.1% after 1, 3 and 5 hrs respectively followed by linalool and Z. armatum and showed remarkable activity at 6 μl/cm2 against P. interpunctella with 76.24±1.1 and 66.42±2.8% repellence after 3 hrs followed by 80.46±1.8 and 72.26±1.4% after an interval of 5 hrs. In progeny deterrence tests alpha pinene and linalool were more potent than others producing 10.25±1.2 and 13.45±2.2 F1 progeny of P. interpunctella with 74.66 and 66.74% deterrent activity even at a lowest concentration of 10 μl/ml, whereas 40.45±4.8 adults emerged successfully in control. Similarly, highest antifeedant activity was revealed for alpha pinene followed by linalool while both the essential oils showed less FDI against the given pest. Responses varied with respect to doses of compounds and exposure time. Further, alpha pinene showed higher toxicity than linalool and it may be attributed to its chemical structure