Repellency and oviposition deterrency effects of garlic and red pepper extract and powder on Plodia interpunctella Hubner under laboratory conditions

Due to the economic importance of stored product pests and disadvantages of chemical insecticides, in this study, the repellency and oviposition deterrency effect of garlic and pepper extract (Tondexir®) and powder was investigated on Plodia interpunctella Hubner (Lep.: Pyralidae). The repellency effect of different concentrations of tondexir (1, 5, 10, 15 and 20%) and garlic and pepper powders was evaluated using Y-shaped olfactometeron adult insects and fourth larval instars, and using leaky glass and petri dish methods on first larval instars, in addition to evaluating the oviposition deterrency effect of these compounds on adult insects. The results showed that 20% concentration of tondexir and garlic powder had the highest repellency effect (63.97% and 58.90%, respectively) on adult insects. The repellency effect of treatments on fourth larval instars was less than that of adult insects. Garlic powder and 20% concentration of tondexir had the highest repellency effect (57.5% and 40%, respectively) on fourth larval instars. Pepper powder showed the highest repellency rate (82.5%) on first larval instars in leaky glass method. The petri dish method had the lowest repellency rate and its highest rate (67.5%) was observed at 20% concentration of tondexir. The highest oviposition deterrency effect of adult insects was related to garlic powder (47.89%) and 20% concentration of tondexir (47.65%). The results of the present study indicated the efficacy of garlic and pepper extract and powder in repelling and the oviposition deterrency of P. interpunctella.