Bemisia tabaci is a major agricultural pest and the usage of essential oil has been suggested as an alternative for the control of agricultural pests, minimizing environmental impact. Thus, the aim of this study was to develop and characterize biodegradable nanoparticles loaded with essential oils from the leaves and fruits of Xylopia aromatica and evaluate their insecticide effect on B. tabaci populations. The essential oils were extracted by hydrodistillation in a Clevenger apparatus, with average yields of 0.05% and 0.8% for leaves and fruits, respectively. Accordingly, the major compounds of the leaf essentials oils were -elemene (38.7%), sabinene (21.46%), α-pinene (7.12%), β-pinene (6.70%) and limonene (2.88%), whereas the major compound of the fruit essential oils was sabinene (69.7%). The nanoprecipitation of a preformed polymer to obtain PCL nanoparticles containing essential oils proved to be effective, with 95% encapsulation efficiency in average. The factorial planning analysis indicated that nanospheres are the best option because they were more economically and environmentally viable. The in vitro release tests showed that after 72 h, diffusion of 75% and 81% of the essential oils of X. aromatica leaves and fruits, respectively. It was observed that the nanospheres substantially protected the essential oil from accelerated degradation caused by UV light. Bioassays showed that both natural and nanoencapsulated essential oils reduced B. tabaci oviposition in bean plants both in the free-choice and in the no-choice tests as the concentration increased. The higher concentration had up to 98% efficacy. Our results suggest that both natural and nanoencapsulated essential oils from X. aromatica leaves and fruits can be used as an alternative for the control of B. tabaci. Additionally, nanotechnology ensures dispersion in an aqueous medium, protects against environmental degradation, prolongs the insecticidal effect through gradual release and may guarantee insecticide activity at a specific active site, thus reducing the development of resistance.