Ozone is a powerful oxidant capable of killing insects and microorganisms has been used in the food processing industry in the gaseous and aqueous states. In a laboratory study, the susceptibility of immature stages of an important stored-product pest, the Indian meal moth, Plodia interpunctella Hubner to ozonated water was investigated. Ozone was applied as aqueous form at four concentrations (0, 2, 3 and 5 ppm) for four different periods (30, 60, 90 and 120 min) on eggs, larvae and pupae of, P. interpunctella. The results indicated that in all tested stages, the rate of mortality increased concomitant with increasing of concentration and exposure time. This study showed that 5-day old larvae were more susceptible than other stages (12-, 17-day old larvae, pupae and eggs) when exposed to 5 ppm ozone for 120 min. Following 5-day old larvae, 12-day old larvae, 17-day old larvae and pupae had the highest sensitivity to ozonation. At the highest concentration of ozone for the longest time, the least mortality rate was recorded for one day old eggs. According to these preliminary results, ozonated water has potential of reducing population density of P. interpunctella, one of the most important pests of dried fruits such as date, almond and pistachio in storage.

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