Nanoemulsified Formulation of Cedrela odorata Essential Oil and Its Larvicidal Effect against Spodoptera frugiperda (J.E. Smith)

Cedrela odorata L. is a plant species from the Meliaceae family that is cultivated for timber production. Although the C. odorata essential oil (EO) contains mainly sesquiterpenes, its insecticidal potential is unknown. The lipophilic properties and high degradation capacity of EOs have limited their application for use in pest control. However, the currently available knowledge on the nanoemulsification of EOs, in addition to the possibility of improving their dispersion, would allow them to prolong their permanence in the field. The objective of the present work was to develop a nanoemulsion of the C. odorata EO and to evaluate its larvicidal activity against Spodoptera frugiperda. The EO was obtained by the hydrodistillation of C. odorata dehydrated leaves, and the nanoemulsion was prepared with non-ionic surfactants (Tween 80 and Span 80) using a combined method of agitation and dispersion with ultrasound. The stability of the nanoemulsion with a droplet diameter of <200 nm was verified in samples stored at 5 °C and 25 °C for 90 days. Both the C. odorata EO and its corresponding nanoemulsion presented lethal properties against S. frugiperda. The results obtained provide guidelines for the use of wood waste to produce sustainable and effective insecticides in the fight against S. frugiperda. In addition, considering that a phytochemical complex mixture allows the simultaneous activation of different action mechanisms, the development of resistance in insects is slower.