Essential oil and antifeedant activity of Zataria multiflora Boiss and Thymus daenensis Celak on Plodia interpunctella Hubner (Lepidoptera: Pyralidae)

In this research, efficiency of plant extracts from Zataria multiflora L. and Thymus daenensis Celak was tested against the Indian meal moth, Plodia interpunctella Hubner for its antifeedant activity. Several experiments were designed to measure the nutritional indices such as relative growth rate (RGR), Relative consumption rate (RCR), efficiency of conversion of ingested food (ECI) and feeding deterrence index (FDI). Treatments were evaluated by the method of flour disk bioassay in the dark, at 25 ± 1º C and 60 ± 5 % R.H. Several concentrations of 0, 0.1, 0.5, 0.75, 1, 1.5 and 2 µL/disk were prepared from each essential oil and 10 first instar larvae (15 days-old larvae) were introduced into each treatment. After 72 hours, nutritional indices were calculated. Results indicated that Z. multiflora oil was highly effective compared to T. daenensis, and significantly decreased the Relative Growth Rate and Relative Consumption Rate. Also, in higher concentration (2 µL/disk), the Efficiency of Conversion of Ingested food (9.384 %) was significantly low. The Z. multiflora oil was more effective on Feeding Deterrence Index than T. daenensis.

Essential oil; Nutritional Indices; Plodia interpunctella; antifeedant activity