Post-harvest management control of Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae): new insights through essential oil encapsulation in cyclodextrin.

Background: Essential oils are reported to be bio-insecticides. However, problems related to their volatility, oxidation and poor water solubility need to be solved before they can be considered as replacement pest control methods. Thus, an appropriate formulation is needed for commercial use. In this work, a new control method based on the use of a powdered cyclodextrin (CD)/1,8-cineole inclusion complex was assessed against larvae and adults of Ectomyelois ceratoniae (Zeller) in comparison with two Rosmarinus officinalis (L.) essential oils, free 1,8-cineole (oils major compound) and a mixture of 50% CD/1,8-cineole inclusion complex and 50% free 1,8-cineole.

Results: Solid CD/1,8-cineole complex was more toxic against E. ceratoniae larvae than the two crude essential oils. At a concentration of 15 µL liter air, the respective mortalities were 94.12%, 35.29% and 19.61% for solid CD/1,8-cineole complex, Thala and Cap Zbib oils after 37 days of exposure. Moreover, the solid CD/1,8-cineole complex achieved 5% adult emergence versus 68.33% for Cap Zbib and 55% for Thala oils. The half-life of solid CD/1,8-cineole inclusion complex (10.98 days) was considerably longer than that of the mixture (7.53 days) or free 1,8-cineole (3.43 days).

Conclusion: This work highlights the utility of essential oil encapsulation in CD to overcome restrictions when used to control the date moth E. ceratoniae during storage. © 2019 Society of Chemical Industry.