Evaluation of Propylene Oxide as an Alternative Fumigant to Methyl Bromide Against Dry Fruit Moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)

Abstract

In this study, the potential use of Propylene Oxide (PPO) as an alternative to MeBr for the rapid control of P. interpunctella was investigated. For this purpose, the insecticidal efficacy of 10 mu l l -1 PPO alone (normal pressure), 10 mu l l -1 PPO+vacuum (100 mm Hg low pressure), and 10 mu l l -1 PPO+cardon dioxide (92% CO 2 concentration) against all biological stages (eggs, larvae, pupae, and adults) of P. interpunctella was evaluated at short exposure times (4 hours) in crop (shelled hazelnuts and dried figs) and crop -free environments. In the biological tests conducted in a product -free environment, PPO+vacuum treatment alone resulted in 100% and near 100% mortality in all biological stages of P. interpunctella (adults, eggs, and pupae) except the larval stage, whereas PPO alone and PPO+CO 2 treatment alone did not result in 100% mortality in any biological stage of P. interpunctella . The results showed that PPO exhibited statistically significantly higher biological efficacy against the pest when applied under a vacuum compared to PPO alone and PPO+CO 2 . Significant differences were also observed between the mortality rates of all treatments against P. interpunctella in crop environments. While the mortality rates ranged from 54.6% to 100% in bioassays with dried figs, low mortality rates ranging from 4.4% to 36% were detected in bioassays with shelled hazelnuts. Overall, this study revealed that PPO+vacuum treatment may be a promising alternative fumigant for rapid control of insect contamination, especially in dried figs.