Efficacy of Eucalyptus essential oils fumigant control against Ectomyelois ceratoniae (Lepidoptera: Pyralidae) under various space occupation conditions

• A comparison chemical study of Eucalyptus camaldulensis and E. leucoxylon essential oils were assessed.
• Results showed that 1,8-Cineole and α-pinene were the major components in both oils.
• Insecticidal activity were tested against last instar larvae and adults of Ectomyelois ceratoniae.
• Fumigant investigation were tested in an empty space, 10%, 50%, 75% and 100% spaces occupied with dates.
• High mortalities were obtained with spaces less occupied with dates, 100% mortality with empty space.

In this work, Eucalyptus camaldulensis and Eucalyptus leucoxylon essential oils were analysed and tested for their fumigant toxicity against adults and last instar larvae of the carob moth Ectomyelois ceratoniae. The effectiveness of the essential oil fumigations against last instar larvae was investigated in an empty space and with 10%, 50%, 75% and 100% spaces occupied with dates.Results showed that larval mortality varied according to the species of Eucalyptus, exposure time and percentage of space occupation with dates. For both oils, high mortalities were obtained after 10 days of exposure and with spaces less occupied with dates (100% mortality with empty space).Fumigation in space 10% occupied with dates was totally effective with E. camaldulensis essential oil, while for E. leucoxylon oil, 94.5% and 98.4% mortally were obtained after respectively 3 and 7 days of exposure. In space 50% occupied with dates, mortality of E. ceratoniae larvae was 93.9% with E. camaldulensis oil against 90.8% with E. leucoxylon oil after 10 days of exposure. In space 100% filled with dates, after 7 and 10 days of exposure to the oils mortality fell to respectively 66.6 and 86.6% for E. camaldulensis and 62.4 and 80.3% for E. leucoxylon. Our work clearly shows the importance of the amount of space occupancy in considering use of Eucalyptus essential oils for postharvest control of the carob moth.