Evaluation of propylene oxide fumigation against Ephestia cautella (Walker, 1863) (Lepidoptera: Pyralidae) in dried figs and hazelnuts

This study aims to investigate the potential use of propylene oxide (PPO) for rapid control of the fig moth, Ephestia cautella (Walker, 1863) (Lepidoptera: Pyralidae). To this end, the biological efficacy of PPO (10 µl/l) against all biological stages of the fig moth was evaluated for a short exposure period (4 hours) under three different conditions: PPO alone (normal pressure), PPO+vacuum (100 mm Hg low pressure), and PPO+CO2 (92% CO2 concentration) in the absence and presence of dried figs and hazelnuts. In the absence of commodities, the biological tests showed 100% mortality rates in all biological stages of E. cautella, except for the pupa stage, when using the PPO+vacuum treatment. However, the PPO alone and PPO+CO2 treatments did not achieve a 100% mortality rate for the biological stages of E. cautella. Conversely, in the presence of dried figs, the mortality rates for all biological stages of E. cautella ranged from 19.7% to 100% in the PPO+vacuum and PPO+CO2 treatments. As for the shelled hazelnuts, all PPO treatments resulted in low mortality rates ranging from 0.7% to 10.6% with PPO+vacuum and PPO+CO2 treatments. In conclusion, the study suggests that the PPO+vacuum treatment can have a viable potential for rapid insect control, particularly in dried figs, making it suitable for quarantine applications.